How to calculate overcurrent protection

Step#2: Select the conductor to comply with Sections 110-14 (c) for “Electrical Connections- Temperature Limitations” and 215. These also include control circuits. Mar 5, 2024 · Figure 5 – Ground-fault overcurrent protection using window CT. Even as a ground current path, the grounded neutral is not necessarily a ground source as it will be herein defined. Step A, Ampacity Rule: Required ampacity at 30°C is 50/0. This requires it to be sized so that locked rotor current will not trip it, and that means it must be sized at about 6x the FLA. If we put too small of a fuse or breaker ahead of this circuit, the breaker could cause a nuisance trip when the equipment turns on. Per 240. 80, “Where a single overcurrent device is used to protect a set of two or more parallel-connected module circuits, the ampacity of each of the module interconnection conductors shall not be less than the sum of the rating of the single fuse plus 125 percent of Overcurrent Protection Devices (OCPD) on Solar Arrays. Apr 1, 2004 · The 16A overload protection device protects the 14 AWG conductors from overcurrent, while the 40A short-circuit protection device protects them from short circuits. Figure 5. There is no intentional time delay set. 32(C) allows the overload device to have a higher size sensing elements or incremental setting or sizing if the overload device selected in 430. Calculate the maximum overcurrent protective device allowed for a non-motorized appliances with the following data: 12 amps and 1∅, 120 volt rating on a circuit breaker. For a polyphase motor, when using an inverse time breaker, you are permitted to use a rating 250 percent of the motor full-load current shown on the motor full Feb 1, 2024 · Inverse-Time Protection. The first portion of 690. Voltage inputs greater than 5V call for a level-shifting circuit between COUT1 and the MOSFET gate. , heater load. E = 480V. Definite (instantaneous)-current protection. Jul 15, 2021 · Transformer overcurrent protection is required to protect the primary windings from short circuits and overloads and the secondary windings from overloads. = 125% Continuous Load + 100% Non-continuous load. Nov 8, 2012 · Those calculations are relatively straightforward and easy to follow. Fast Protection Minimizes • Temperature rise • Mechanical damage from magnetic forces • Voltage sag Apr 1, 2018 · According to the Canadian Electrical Code, I will need to account for inrush current at no more than 250% for the overcurrent Protection. Special attention is paid to instantaneous and time delay protection types (normal, very and extremely inverse relays). ) 225% of the largest motor FLA + the remaining sum. If the motor speed range is greater than 2:1, program [Overload Mode] to the proper derate. The following table shows a summary of fault duties and how they are used. • Power Circuit—a power circuit is every circuit minus the control circuits. A minimum total operating time provides fast protection and enhances the reliability of the network. The next Code section, 690. Both types of control restrict the amount of current that Jul 29, 2021 · The characteristics of overcurrent relays are based on operating times typically governed by a time vs. A. 32(A)(1) and 430. 70 + (5. Perhaps the most basic and necessary protective relay function is overcurrent: commanding a circuit breaker to trip when the line current becomes excessive. Hence the formula can be written as, T (s) = TSM * (k / ( (I (F) /Is (A) ) α In this video we have explained calculation for IDMT over current relay setting calculation. Proper sizing of the circuit protection is the first step. Supply wiring must be rated to carry at least the amps shown as MCA. Jan 20, 2020 · Calculation of PSM Method – 1: Example-1: Old CT Ratio- 75/1 A, PSM – 0. 1 ). 75. Feb 25, 2019 · For decades, electromechanical negative sequence overcurrent relays have been provided as standard unbalanced current protection for moderate and large generators. 25%. Jul 17, 2019 · Motor Calculations — Part 1. If you get a short circuit or ground fault, the increase in current is dramatic. Step 4. Never underestimate how important it is to choose the right CT size in fault detection and protection (photo credit: pfiffner-group. A simple convection heater system, using only a heater and blower or fan, can be effectively protected with a circuit breaker. Aug 17, 2012 · Needless to say, the NEC covers all aspects of overcurrent protection where electrical safety is an issue (Art. 112-1996 protection curves. When electromechanical relays were more popular, the overcurrent protection was made up from separate single-phase units. Get recommendations on SPD ratings. Four corner testing means in this case means high and low voltage permuted with high and low temperature. To change the Old Current Transformer with the New Current Transformer the following procedure is taken. Click the “Calculate” button to obtain the accurate relay settings. - Appliance Rating: 12. Step B, 125% Rule: 1. . The overloads are designed to protect the motor under overload conditions by removing the motor from the circuit in the event of an over load condition. 5 amperes at 240-volts. This calculator allows you to choose both U. I for Star values: 3. Overcurrent relays are normally supplied with an instantaneous element and a time-delay element within the same unit. However, more complicated systems that add controls tend to need more complex protection. As we’ll see, when selecting an OCPD . NOTE. Aug 30, 2022 · National Electrical Code Basics: Overcurrent Protection Part 1. May 16, 2016 · 18A × 1. This is called the branch-circuit short-circuit and ground-fault protection and is determined using Table 430. Every electric circuit must have overcurrent protection , whether a high-voltage transmission line carries many amperes or a low-voltage lighting circuit passes a few amperes. 25 = 11. To use the Over Current Relay Setting Calculator, follow these simple steps: Enter the rated current of the system in the designated input field. 52. Sep 24, 2019 · Spec Note The generator set shall be provided with an overcurrent protective device that is coordinated with the alternator to prevent damage on any possible overload or overcurrent condition external to the machine. The Inverse Time Over Current (TOC/IDMT) relay trip time calculator calculates the protection trip time according to IEC 60255 and IEEE C37. 91/1. 25A. 10 A. Dec 26, 2016 · 1. MCA = 1. There will be some information about sizing the PV wires, but a detailed discussion wire sizing is beyond the scope of this paper. 3(B), it has to be 167% of the primary current. If the 30A short-circuit and ground-fault protection device isn’t capable of carrying the starting current, then you can size the protective device up to 225% of the equipment load current rating. Overcurrent protection and disconnects. 3 Setting Overcurrent Relays. Mar 28, 2024 · Protection Against Over voltages. You could, with most motors, use a 175% sized fusible disconnect switch and Jan 4, 2024 · How to Use. 25 * (Motor FLA + Heater Current) MOCP. Jun 8, 2017 · Product Line: MCCB Resolution: Per the NEC 695. The electromechanical technology severely limited the sensitivity of these relay. The real source for ground fault current is the combination of the power system positive sequence generation to provide the fault current Sep 23, 2020 · The thought is that the conductor sizing should match the overcurrent protection device size. This relay is referred as definite (instantaneous) overcurrent relay. and IEC curves. Now we can calculate primary protection. 21 lessons in 3 hours and 29 minutes. All elements are independent of each other and can be combined in any way. Go back to Contents Table ↑. In this proposed work, the total operating time is obtained only 7. Depending on the device’s characteristics, during the short-circuit, the collector current can be kept at or below a certain level, however the IGBT will secondary overcurrent protection Overcurrent devices are used between the output terminals of the transformer and the load for three reasons: 1. Jun 2, 2019 · For modern distribution protection, Negative Phase Sequence (NPS) Protection is often relegated in favor of common elements such as Overcurrent (OC) or Earth Fault (EF), but NPS is an incredibly powerful function itself which adds selectivity and specificity to protection schemes with the capability to detect faults completely missed by common elements, says Oswaldo Kaschny, vice president of Mar 9, 2018 · sequence overcurrent (51Q) protection. 240, Overcurrent Protection). Example: Let’s consider an example where you need to set the overcurrent relay for a motor rated at 100 amps operating at 480 volts with a desired protection level of 150% of the rated current: Overcurrent setting (I>) = (Multiplying factor) x (Rated current) Using a multiplying factor of 1. The operating philosophy of the DC power system determines the design and type of overcurrent protection used. Jan 28, 2009 · Electronic overload protection is factory set to drive maximum. For example, 40A x 1. You can run secondary conductors without secondary overcurrent protection at the point of supply for 10 ft if the secondary conductors have an ampacity greater than the rating of the termination device. 3 Overcurrent protection. Overcurrent relay protection is given at B, C, D and E, that is, at the infeed position of each part of the electrical power system. Use a 3P125A breaker for the secondary protection This means that since you have a range with a rating more than 8 3/4 kW, the minimum circuit rating is 40 amperes. To protect the SCR against the transient over voltages, a parallel R-C snubber network is provided for each SCR in a converter circuit. 3 (Transformer protection). 732) = 90 x 1. Apr 6, 2022 · There are two main types of overcurrent protection devices, circuit breakers and fuses. 70) × 0. The NEC allows for the overcurrent protection device to exceed the rating of the conductors to allow for motor in-rush current. 6 = 5. Sep 5, 2020 · You can use our solar wire calculator to select your wire. Now we must determine the motor branch-circuit overcurrent protection. 5 x 100 amps = 150 amps. Applying directional overcurrent relays in ground fault protection of transmission lines. Solar panels parameters The Time Overcurrent Relay Operate Time Calculator will calculate the operate time for a time overcurrent relay given the curve, time dial, pickup, and fault current. Jul 19, 2016 · The basic process to select the right overcurrent protective device (OCPD) for this discussion of 80% rated versus 100% rated, begins with a calculation of the load, includes a journey through conductor selection based on the calculated load current, and ends with the right OCPD to protect the conductor. Mar 20, 2022 · In order to determine the appropriate wire size for a particular circuit there are four main considerations that must be evaluated in phases: Maximum circuit current. To properly set the electronic overload protection, program [Overload Amps] (Setup group) to the actual nameplate F. Since short circuit current is minimized, a smaller gauge wire may be used between the transformer and the load. Motor overload protection is necessary to protect the motor and to help ensure the motor performs as expected. Be the first to add your personal experience. What is the WOLF method? Well it is a simple way to size the conductors as well as s Dec 11, 2012 · As noted in this example, "The overcurrent protection device must accommodate 125% of the continuous load, plus the noncontinuous load. Minimum OCPD is 14. The full program code explanation is done below. New CT Ratio- 100/5A. See Circuit Breaker Criteria table below for standard sizes suitable for SolarEdge three phase inverters. Introduction; Overcurrent protection of transformers >600V (NEC450. Not over 800A. Practical Example Of Overcurrent Protection Devices Sizing In A Typical RV Solar Power System. S. The overcurrent protection device, either a breaker or fuses, must be sized to prevent the unit from drawing more current than the MOP. There is always an inherent time delay of the order of a few milliseconds. 30 + (2. 0. Specify the plug setting multiplier (PSM) and time dial setting (TDS) values. Jul 2, 2018 · The motor’s full-load current, the nameplate FLA, is used to calculate separate motor overload protection, 430. 25 x [Motor Rated Current + Heater Current] The “Motor Rated Current” is motor data. com) An exact 100% rated for 30A circuit breaker can be used for 30A non-continuous load. Each phase current and the ground current is provided with three elements. When an electrical surge occurs, voltage greatly exceeding accepted peak voltage levels could pass through building circuits to electrical equipment. Each relay protection device comprises a definite-time delay overcurrent protection relay in which the trip of the current sensitive element starts the time delay The fault current flows into the non-polarity mark of the CT connected to Circuit Breaker 4, so the Directional Overcurrent (67) relay sees the fault in the reverse direction. Voltage drop. Don’t confuse overload protection with short-circuit and ground-fault protection. I am not aware of an 18-ampere circuit breaker. This code combines several components and libraries to create an overcurrent protection system with a current sensor (ZMCT103C), a relay, a potentiometer, and an OLED display. = 56. Typical Single Phase & Three Phase Motor Data: Provides typical FLA, SC protection, conductor size, and motor starter information. Now we can calculate primary current: Primary current = VA ÷ E = 1,500VA ÷ 480V = 3. Step 3: Calculate Learn how overcurrent protection works in power systems, the concept of short circuits, different types of faults, and settings. Example 2: CB Size for 28A Contentious Load. Overcurrent protection is designed to protect the system from the intolerable conditions associated with short-circuits. Information on the available fault duties is important when performing a protection coordination study. This snubber network protects the SCR against internal over voltages that are caused during the reverse recovery process. Earth-fault (50/51N) overcurrent protection for the capacitor bus and bank. Branch Circuit Conductor and Overcurrent Protection Calculator, Mobile Desktop Version Continuous Load, Amps Non-Continuous Load, Amps No. The motor branch-circuit short-circuit and ground-fault protective device shall be capable of carrying the starting current of the motor. Feb 1, 2008 · To calculate the primary OCPD size, first we need to calculate the primary current. Motors and their associated equipment must be protected against both overload and overcurrent (short circuit or ground fault). In both motor circuits and non-motor circuits, the OCPD protects the circuit against this Aug 28, 2017 · Figure 5 shows a typical overcurrent protection circuit diagram. 25 x 50 = 62. Jan 16, 2011 · PV containers may operate above 40°C. The more modern microprocessor protection has a three-phase overcurrent Multiply the inverter's maximum continuous output current by the factor. Overcurrent directional relays can be set to trip for faults in the forward Aug 14, 2018 · They protect the motor branch-circuit, the wires between the last over-current protection device (OCPD) and the motor, in the event of a short-circuit or ground-fault. In the event of a short circuit, first the IGBT’s collector current will rise, once it has reached a certain level, the C-E voltage will spike. Each relay protection device comprises a definite-time delay overcurrent protection relay in which the trip of the current sensitive element starts the time delay device. Overcurrent Protection for Phase and Earthfaults Protection against excess current was naturally the earliest protection system to evolve. Jan 22, 2024 · Arduino Program Code. If the current flowing through the protection device exceeds the device setting for a significant period, the protection device will open. 25 = 18. Updated in 2011, this portion of the Code covers the requirements for overcurrent protection device and conductor sizing. 2 Time-overcurrent ground-fault protection. ½ Cycle. 9 amps and this would require an 8 AWG cable. Overcurrent protection requirements depend upon several factors that will be outlined in this article. 25 = 40. 5 = 2682A. 28 = 5. 3A) Unsupervised location of transformer (impedance <6%) Unsupervised location of transformer (impedance 6% to 10%) May 18, 2021 · Surge protection device (SPD) help is available in Cascading Surge Suppression IEEE Standard 1100. 25 x 28 A = 35A. Per 450. SPDs should be in at every level. There are three principal components of an electrical circuit: a power source, a load, and a connection between the two. The relay operates as soon as the current gets higher than a preset value. 4(B), a fire pump breaker has to be sized so that it provides short-circuit protection only. 00 – 5. Therefore the New PSM value is = 0. Round up the rated size, as calculated in step 1, to the closest standard circuit breaker size. How To Calculate Overcurrent Protection. • Control Circuit—control circuits perform the on/off and other control functions in a panel. The NEC allows for a single overcurrent protection device for motor overload, motor branch short circuit and ground faults. These phases will be carried out in this order. Jun 2, 2010 · Other than any OCP the generator manufacturer might request your OCP would serve as the protection for the conductors from the gererator to the load and size accordingly. 5. (NEC 430-52b) Yes, your eqipment does have to be sized to carry the starting current. This article focuses on the calculation of CT sizing specifically for dual power overcurrent relays, aiming to ensure effective protection and fault detection in power systems. 3) This technical article was written by author Jignesh Parmar explains step by step NEC 450. We calculate loads as VA, not as amps, but we size OCPDs in amps. g. 90 – 3. We can call them as overcurrents. 5625. The MOCP is the measured value that is used to determines the maximum size of the overcurrent protection devices such as circuit breaker or fuse that is used to protect the wire and equipment under fault conditions. 125 A. Instantaneous relays have operating times usually less than 3 cycles. Sensitive ground time overcurrent protection (64) supervised by a 3V0 (59N) element measuring the bus voltage which provides backup protection for each stack. 732)= 208 x 1. Radial electrical system with time discrimination. To do that, we need to know a couple of things: VA = 1,500VA. 50A, next size down = 30A. Time-Current Curves Protective Device Coordination. Wire ampacity. Minimum Circuit Ampacity (MCA) for both fan-powered and heater-only products is calculated with the following equation: MCA = 1. 5A. This should not be confused with ‘overload’ protection, which normally makes use of relays Apr 15, 2023 · Maximum Overcurrent Protection (MOCP or MOP) Maximum Overcurrent Protection, or MOCP, is the maximum size of a fuse or circuit breaker required to provide adequate protection of the equipment during a fault condition. Oct 1, 2007 · Conductor overload protection is not required where circuit interruption would create a hazard (e. The datasheet in Figure 5 states that the maximum output current is 14. To size feeder (and service) conductors and overcurrent protection, loads must first be calculated in accordance with Part III or Part IV of Article 220. The current value of the protection should be 125% of the maximum I for Delta values: 5. Over current relaying and fuse protection uses the principle that when the current exceeds a predetermined value, it indicates presence of a fault (short circuit). 75% of 75A =75 * 0. As mentioned in parameters, a Time Dial Multiplier (TDM) is sometimes specified by the relay manufacturer instead of a Time Dial (TD). 13A. The purpose of overcurrent protection is to guard against power distribution equipment damage, due to the fact that excessive current in a power system dissipates excessive heat in the metal conductors comprising that system. You can use the next higher standard rating overcurrent device (above the ampacity of the ungrounded conductors being protected) if all of the following conditions are met: May 1, 2004 · When the protection device values determined from Table 430. of Current Carrying Conductors Mar 19, 2015 · Overcurrent is a condition where the current exceeds the rating of equipment or ampacity of a conductor due to overload, short circuit, or ground fault [Art. Step 1: Identify the protection devices. 18A × 2. 25 = 260A Use a 3P300A breaker for the primary protection Secondary overcurrent protection - 75KVA/831 (480x1. 33 amperes, the circuit cannot be less than 40 amperes. To illustrate this, let's use the same motor as in the previous example. There are three main types of overcurrent relay: (1) Instantaneous, (2) Time-Dependent (Definite time or inverse), and (3) Mixed (Definite time and Inverse). Nov 18, 2019 · Protection Basics: Overcurrent Protection . Overcurrent protection. Licensed electricians spend years learning the nuances of overcurrent protection, like how to determine the OCPD and the conductor size needed for that OCPD. How to size motor branch circuit overcurrent protection per the national electrical code. Rule-of-thumb: The external motor overload relay is always set to the nominal current Overcurrent Protection of Transformer (NEC 450. Aug 1, 1996 · Unless listed for operation at 100% of a continuous load, the overcurrent protective device must be rated at least 125% of the continuous portion of the load, plus 100% of the noncontinuous portion. which is reduced by Aug 3, 2009 · MOP = Maximum overcurrent protection (The maximum overcurrent protection (MOP) is the maximum circuit breaker / fuse size required to properly protect the equipment under anticipated fault conditions. See conversion here. 6(A), you must use the next higher overcurrent protection device. In case of continuous load, rate of %125 is applicable. The big difference is this: fuses are used up after one overcurrent event and breakers are reusable. 2. 8(B), is where most people start to get confused. It means for 100A–56. - Voltage Rating: 1∅, 120 volts. - OCPD: Circuit Breaker. This paper describes when and why PV fuses/breakers are needed and provides high level information on sizing the PV fuse/breakers. The reset time is also provided. Knowledge of circuit breakers for overcurrent protection and their ratings that are available for DC application are also essential. Mar 1, 2022 · Per the Code reference, the minimum rating for the PV inverter (AC) overcurrent device is 125% of the rated inverter continuous output. Article 240 of the National Electrical Code is all about overcurrent protection devices. 2 for “Feeders Minimum Rating and Size”. Protect the transformer from load electrical anomalies. This example illustrates the sometimes confusing fact that when you're doing motor calculations, you're actually calculating overcurrent and short-circuit protection separately. Jul 1, 2002 · 112. 25 times the FLA of the motor adding in all other resistive loads i. • Branch Circuit—branch circuits run from the branch overcurrent protection device to the load. NEC® Section 450. 122, 175A primary protection (Step 2) requires a 6 AWG copper conductor. How We Calculate MCA and MOP These two values are published on the nameplate to insure proper wire sizing and safe operation. As a result, they could provide only backup protection for uncleared phase-to-phase and ground faults. B. This is required to control the external MOSFET as 5V is the maximum pullup voltage on COUT1. From this basic principle, the graded overcurrent system, a discriminative fault protection, has been developed. 55 to calculate a rating of 33. Overcurrent protection covers phase and ground faults. The topic is straightforward and easy to understand, but it is essential that design and installation work be done correctly if the protection is to be meaningful. 30 A. e. 5kVA transformer — Per Table 250. " When you multiply your continuous load by 125% and then add it to the total of the noncontinuous load, you get your total VA. 52 don't correspond with the standard rating of overcurrent protection devices listed in 240. Therefore, you can use a 30A or 40A overcurrent device to Sizing of Module Interconnection Conductors and DC Over Current Protection NEC 690. 32(B)(1 Jan 25, 2023 · You can calculate what you think the worst case current consumption is, and then build out 5 or 10 units and do 4 corner testing (or maybe more corners). Therefore, 1073A * 2. 728 s. Sep 1, 2007 · The battery circuit breaker is normally installed to provide both disconnect and protection capabilities. Can I get away with using a 1600A breaker that has an adjustable trip setting? Note that my transformer is sized at 450KVA. 75 = 31. Oct 4, 2022 · How to size motor feeder overcurrent protection per the national electrical code. 20 and Part II of Article 220. Short-circuit protection is still required. 8 determines the overcurrent device ratings. 5 amps and this would indicate a 6 AWG cable. MAX4373 overcurrent protection circuit. - Connected Load: Amps. 6(A)(2): Separate motor overload protection shall be based on the motor nameplate current rating. Temperature correction factor = 0. This function is usually split, with separate devices for overload protection and short-circuit/ground In this video we talk about how to size a motor using the WOLF method. , a fire pump). Sep 23, 2020 · Because there are no standard sizes between 20- and 25-amp ratings, a 20-amp fuse or circuit breaker is the correct size for the single overcurrent protection device. 25= 50A. 6 = 3. Example 3: CB Size for 30A Non-contentious Load & 28A contentious Load. Overcurrent rating. So that is hot and high, hot and low, cold and high, and finally, cold and low. Some devices must protect conductors and equipment from overloads and short-circuits. Protective Device Coordination Study- Description: An organized time-current study of protective devices from the utility to a device. These calculations are required for successful implementation of Sizing of branch-circuit overcurrent protective devices must be done in accordance with 210. Jul 18, 2003 · Re: Elevator Overcurrent Sizing (B) All Motors. Oct 27, 2017 · The Form and Function of Overcurrent Protection Devices. The overcurrent rating of an OCPD is listed in amperes, such as 15A, 20A, or 30A. 0 = 54. So despite the fact that you used Table 220. Let’s apply the above-mentioned overcurrent protection guidelines on the following RV system: Typical RV solar power system with fuses for overcurrent protection. This scheme is based on the intuition that, faults typically short circuits, lead to currents much above the load current. 06 = 3. 1. 100] ( Fig. Step 2: Define the protection zones. The overcurrent protective device may be rounded up to the next higher standard size, subject to the usual 800 A limitation. 3 contains the requirements for overcurrent protection of transformers. Many installations have surge protection at the motor terminals, and a surge discharge through an arrester could cause an instantaneous relay to have a false trip. L. My question is, the cutsheets says there is 0 in rush. The generator 480v output if I did my math correctly is 150 amps but the OCP device you install will also dependant on what the generator is supplying (motors, fire pumps, etc) Jul 28, 2011 · Primary overcurrent protection - 75KVA/360 (208x1. General time overcurrent protection is one of the main functions of a protective relay. Therefore, you'll install conductors rated for 40 amperes, and a 40 ampere overcurrent device. 6(A), multiply 34A×175% 1-1 Short circuit withstand capability. The schematic symbols for breakers and fuses are here for reference: Mar 5, 2019 · The overcurrent protection device, either a breaker or fuses, must be sized to prevent the unit from drawing more current than the MOP. Dec 1, 2000 · Overcurrent protection devices have two current ratings: overcurrent and amperes interrupting current (AIC). Step#1: Size the overcurrent protection device in accordance with Sections 210-20 (a) for “Overcurrent Protection - Continuous and Noncontinuous Loads”. 30) × 0. The orange/red shaded region indicates the typical region for a fault behind a relay. 50A, next size down 40A. 5 A x 1. Breaker failure protection of the main disconnect device. This is the Arduino Program code for the Overcurrent Protection Circuit using Arduino & CT Sensor. A comparison of the time it takes protective devices to operate when certain levels of normal or abnormal current pass through them. The protective device shall be listed as a utility grade protective device under UL category NRGU. A. 5 (for 150% protection): I> = 1. current curve. These three principal components are supplemented with a means of ON/OFF control and a means of limit control. NEC 240. 91, Conduit fill correction factor = 1. Here, as defined in IEC 60255, the IDMT Tripping Time T (s) is multiplication of Time Setting Multiplier (TSM) by the k curve constant divided by the division of fault current I (F) in Amps to relay Current setting Is (A) in amps power of curve constant α minus 1. The values for the full-load current correspond to the permissible full-load current of the motor at 254 ∆/440 Y V, 60 Hz. Nov 15, 2020 · The value of MCA is the 1. 3. so gf ag ha nh cf kq ue dh no