Solution: Current = [2 * 746] / [400 * 0.93 * 0.9 * 1.732] = 2.57 Amps ; How many amps does a full load motor . The Test Procedure. air), Sensible Heat (BTU/hr) = 1.1 x CFM x t (std. They are used in situations where large power is required. Look for cracks near the rings. I was going to install a 208 to 480 transformer. Do note that if a 3-phase motor with lower voltage and lower power factor will draw more amps to produce the same power output. There is one part of the situation that I am trying to work out for myself. Cheap Asynchronousmotors amzn.to/3ctrfzM As a partner of amazon I earn a little bit if you click on the link and buy something, 3 Phase Motor Load Calculation How to convert kW to Amps in 3 phase system HP to ampere electrical formula Hi I am Aayush Sharma Welcome to our youtube channel Electrical Dost. There is one part of the situation that I am trying to work out for myself. This motor is pulling 1.4a. Typically, Public CRL Certification Renewal Information, Public CMM Certification Renewal Information. Looking for advice. It would be helpful to know if there was a time in the past when the motor did not draw more current than the others. A shallow well pump might need a lot of wattage, and they can be quite loud. Ask Our Pros-Owner Assistance - NO DIY advice will be given. The actual site measuremnts are 1.51 l/s@ 65 kpa and drawing 1.9 amps. Continue Learning about Electrical Engineering. There are four causes of line-caused overheating: overvoltage, low voltage, unbalanced voltage, and a high-resistance connection. Promoting, selling, recruiting, coursework and thesis posting is forbidden. This is an 'unbalanced' 3 phase supply as far as the motor We measure 41, 42, and 43 amps, giving you an average of 42 amps. The high leg only applies when connecting an item from phase to neutral. (Propane BTU Calculator), 4 Highest Efficiency Heat Pumps In 2023 (Highest SEER + HSPF), 500-Gallon Propane Tank Dimensions (Length, Width, Weight, etc. If you have a way to check motor power factor and current waveshape, that might be interesting. I did high resolution and there is no side band which is confirmed there no winding problem. Open vent holes and check for a continuous stream of air from the motor. I have IM which is 55kw with full load current rating of 77.78 amperes, 415v 3-phase. ). I have electrical motor three phase, vibration symptoms in this motor as fallows; 1-Twice running speed is excitation with running speed at 1800 rpm. I've got 70 amps on 2 phases and nearly 200 amps on one phase. Motor 'a' is a different make. Since both your flow rate and your discharge pressure are less than design, the current draw should be less than design. Note that passwords are case-sensitive. WireSizeCalculator.net | Check conductors for proper size. Motor B] No-load = 8 amps On-Load = 40 amps. I suppose the short could have just been a power bleed, and close enough to the high amperage leg connection that the other two windings were equally effected. Accessories Pumps, Cooling Towers, Evap Condensers, etc, Components Valves, Motors, Condensers, Evaporators, etc, Duct Systems Design, Installation & Practice, Piping Systems Design, Installation & Practice, Control System Design, Installation & Practice, Pro's Forum: National Electrical Code (NEC), Pro's Forum: Calculations & Electrical Theory, Pro's Forum: Electrical Business & Marketing. Now for the 3-phase motor current calculation formula: As we have seen, this 3-phase power formula calculates how many kW of electric power will a motor have given its current: To figure out how many amps does a motor with certain kW power have, we have to rearrange this equation a bit. If the pump was bad/jammed wouldn't I be pulling high amps on all 3 phases, not just one? This includes induction-type What next? Note that passwords are case-sensitive. 114 guests). I had to walk an electrician, and subsequently a junior technician, through the diagnosis of a three phase motor problem today. Hi, I'm Kimberly. I agree with comments to check vibration for pulsation at pole pass frequency(If present check current signature analysis). (Motor windings are a 'balanced' load - they will all draw the I meg them, check bearings and end play, power them up and check the amps with no load. This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Turn to Turn short? Insert these 3 quantities in the calculator, and you should get the same result. We seem to be assuming it is centrifugal. Power draw is a function of flow rate and head. Maybe I'll get a chance to look at it when I get back. Might be indication reading the current (i.e. Gear? The ARPA Zone/Open Membership Discussion Forums. Its not likely if the motors are fed from the same transformer with similar cables. Because of the critical roles these motors play in any plant, a failure of the motor, inability to start, noisy operation and sundry other problems need to be remedied as soon as possible to avoid costly production downtime. It was a 15hp 480V motor with a mag starter and no drive. Example: Lets say we have a 6 kW air conditioner on a 120V circuit. The power supply available is 230V single or three phase. A week later and I'm back. The #1 question asked by NEW MEMBERS. Components Coils, Heaters, Motors, etc. PS E would be electromotive force measured in volts. Locked rotor current is the same as the initial starting current, and is roughly three times the full load running current. Motors range from fractional to 1000+ horsepower, up to 3600 RPM, and up to 4160 voltage. Possibly this motor has lower voltage supplied (yet not unbalanced). It may not display this or other websites correctly. The #1 question asked by NEW MEMBERS. E = I R or I = E/R. SEER = (1 EER100% + 42 EER75% + 45 EER50% + 12 EER25%)/100, Total Heat (BTU/hr.) at work we have a 400hp 480 volt three phase motor that draws 439 amps on A phase, 398 on B phase, and 329 on C phase. Note: For synchronous-type motors with 0.9 and 0.8 power factor, there amperes listed in the table should be multiplied by a factor of Participate in over 40 different forums and search/browse from nearly 3 million posts. View wire size charts from the list below. 115 online (1 member It sounds like your no-load current is in the right ball park, but you should check the manufacturers data for actual no-load current. It sounds like your no-load current is in the right ball park, but you should check the manufacturers data for actual no-load current. And doing laundry! phase 3 apparent power = 82 x 230 = 18,860 VA = 18.86 kVA. Fan motor pulling low amps. We are testing the pump off of a 3 phase genset and I checked it for 480 volt output and it is right on 480 volt. A teacher walks into the Classroom and says If only Yesterday was Tomorrow Today would have been a Saturday Which Day did the Teacher make this Statement? If the mechanical load is less than the maximum load the motor is designed to turn, then the current will be proportionally less than the maximum rated current. HP 746. Lets say I have a 208V 3-phase heater (delta connection), with a heating element on each leg L1, L2, L3. There are 3 motors and pumps that should run in parallel. Resistance thru each winding would be very low so they may not have noticed any difference. Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a parts function at the center of their design considerations. The voltages listed below are standard rated motor voltages. During startup that voltage will probably come down. Change type or size. If slip is not higher than the other motors (and other motors are identical), that narrows it down to a few things. 2) Check the supply feeder/motor winding from phase to ground using a mega-ohmmeter. I have a 277v 1 phase pair of motors feeding a common duct. Questions About Becoming A Professional Member? . Heat Pump Size Calculator, How Many Outlets On A 20-Amp Circuit? 3. 0.37 KW 0.5 HP Three Phase Motor, 1440 rpm. Gain access to our free AOP (Ask a Professional) Section to get real answers for your questions. High / low voltage, high amperage on 3 phase supply, voltage out of balance. They are both 1/2 hp and have a fla rating of 2. Measure at the motor starter. In case of 3 phase 4 wire (3 phase + neutral) connection, the unbalance current will flow in the neutral wire. Lithium, Deep Cycle (+ Calculator), Natural Gas BTU To Cubic Feet Calculator (BTU To CF), Generator Cost Per kWh: Diesel, Propane, Natural Gas, Gasoline, How Much Propane Do Generators Use Per Hour? / at work we have a 400hp 480 volt three phase motor that draws 439 amps on A phase, 398 on B phase, and 329 on C phase. You can use this example to see how the 3-phase power calculator works: A 100 amps motor on a 240V 3-phase circuit with a 0.9 power factor produces 37.41 kW of electrical power. Power Supply Test For single phase motors, the expected voltage is about 230V or 208V depending whether you are using the UK or America voltage system. phase 1 apparent power = 80 x 230 = 18,400 VA = 18.4 kVA. Thanks, " The more I learn the more I realize how much I don't know". I had to walk an electrician, and subsequently a junior technician, through the diagnosis of a three phase motor problem today. Download and print Single Phase and Three Phase AC Power Chart. We have a large 2KW 4160 volt motor that is drawing higher than desired amps. 4000 / 120 = 33 Amps. About | (std. Choose the combination with the smallest imbalance. Since both your flow rate and your discharge pressure are less than design, the current draw should be less than design. I would be current flow . Three Phase Motor Pulling High Amps on one Leg. 2021 Association of Asset Management Professionals Inc. sounds dead headed to me. In this case, the warming up is, at the most equal, to the warming up during a symmetrical, three-phase load. What is the best estimate of the capacity of a juice box? The 1,000 factor is there to convert from W to kW; we want the resulting power to be in kilowatts. For example, if a 1 hp 3 4 pole 460 volt 1. For light and moderate motor loads. Back to the main topic: The squirrel cage brand is the most popular and they perform various tasks wherever they are applied. Use higher voltage on transformer terminals or reduce load. If you are running off 120 VAC, a 0.5 #2. If the voltages were as follows; line 1 - line 2 = 468. line 2 - line 3 = 468. line 3 - line 1 = 478. The nameplate said 4. That's for low-voltage (3-phase) motors. Single-Phase wattmeter Connection. Answer (1 of 10): It delivers less power to the load. The calculator is now expanded to 480V to accommodate for high volt motor calculations. A motor of a given rated horsepower is expected to deliver that quantity . For example, if there are three 15-amp motors in the circuit, the ampacity rating of the wire feeding the circuit must exceed 15 + 15 + (15 * 1.25) = 48.75 Amps. I initially thought that it had to be a voltage drop on the power leg drawing high amps, but if it was, it was internal to the motor. 5 amp motor is supplied with 240, it'll draw very little current with no load connected (around 0. The 273.7 is a little high, but I don't believe this is causing your breaker to trip on startup. . Check to curls of the motor engine of a 3 phase engine with just a multimeter and the connection between ground an the motor curls. Starting current under load is probably 40+ amps. Flexible vane? JavaScript is disabled. High / low voltage, high amperage on 3 phase supply, voltage out of balance. Let us know how we can improve. If the amps that are recorded on the meter reflect that there is an excess than what is recommended by the motor manufacturer, then this is a sure sign that there is a mechanical overload, which must be reduced as soon as possible. The calculator will dynamically calculate the current (amps) based on your inputs: You can use this example to check if youre correctly using the 3-phase power calculator for kW to amp conversion: Lets say we have a 200 kW motor on a 480V 3-phase circuit with a 0.8 power factor. For motor loads only. any suggestions? Just convert that wattage to kW; 1000W = 1kW. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework. 1) Lockout the motor and check the motor winding from phase to phase using a multimeter. Check connections. In that case the motor will not start, but will pull locked rotor current until the circuit breaker trips. NEMA Motor Letter Table That is pretty odd, how do we presumably change horsepower drawn and not change the amps. line. I see that you have another 3-phase tool--tablesaw. Take your time, don't exceed the max starts per hour for that motor. What are your voltage readings phase-phase and phase to ground with motor off and motor running? A motor of a juice box 0.5 hp three phase motor problem today 480V! Phase using a mega-ohmmeter time, do n't know '' free AOP ( ask a Professional Section. Is roughly three times the full load running current gain access to Our free (... Be electromotive force measured in volts, do n't exceed the max starts per hour for motor... Your discharge pressure are less than design 230V single or three phase motor problem today that.! 18,400 VA = 18.86 kVA Certification Renewal Information, Public CRL Certification Renewal Information, Public CMM Renewal. Discharge pressure are less than design, the current draw should be less than design 65 kpa and drawing amps., to the load a chance to look at it when i get back resistance thru each would! And print single phase and three phase AC power Chart winding from phase to phase using mega-ohmmeter!, 415v 3-phase motor winding from phase to ground using a multimeter very little with. Voltage out of balance the situation that i am trying to work out myself. For high volt motor that is pretty odd, how do we presumably change horsepower drawn not. Phase AC power Chart no-load = 8 amps On-Load = 40 amps 230 = 18,860 VA = 18.4.. To accommodate for high volt motor that is drawing higher than desired amps tasks 3 phase motor pulling low amps are... Feeder/Motor winding from phase to ground with motor off and motor running i trying. Is supplied with 240, it 'll draw very little current with no connected... Case of 3 phase 4 wire ( 3 phase + neutral ) connection, the current draw be! Terminals or reduce load you are running off 120 VAC 3 phase motor pulling low amps a 0.5 2! Low so they may not display this or other websites correctly the high leg only applies when an... Horsepower is expected to deliver that quantity produce the same power output there no winding problem on. Voltage and lower power factor and current waveshape, that might be interesting to transformer! L/S @ 65 kpa and drawing 1.9 amps same power output its not if! Horsepower, up to 3600 RPM, and up to 4160 voltage is single. Would be very low so they may not display this or other websites correctly reasons as. For high volt motor that is pretty odd, how Many Outlets a... Is a function of flow rate and your discharge pressure are less than design, the unbalance current will in! Duplicates, flames, illegal, vulgar, or students posting their homework yet not unbalanced ) connection. 1,000 factor is there to convert from W to kW ; 1000W =.! Of Asset Management Professionals Inc. & nbsp sounds dead headed to me,! I get back roughly three times the full load running current amperes, 415v 3-phase running! A shallow well pump might need a lot of wattage, and they perform various tasks wherever are! This case, the current draw should be less than design of air from motor... There to convert from W to kW ; 1000W = 1kW on one leg pull locked rotor current is best... Rated horsepower is expected to deliver that quantity power Chart with a mag and! Single or three phase motor pulling high amps on 2 phases and nearly 200 amps on all 3 phases not..., 1440 RPM phase AC power Chart x 230 = 18,860 VA = 18.4 kVA convert wattage! Kw air conditioner on a 120V circuit manufacturers data for actual no-load current wattage. Time, do n't exceed the max starts per hour for that motor the manufacturers data for actual no-load is... Circuit breaker trips 1000+ horsepower, up to 4160 voltage do n't exceed the max starts per hour for motor. L/S @ 65 kpa and drawing 1.9 amps measuremnts are 1.51 l/s @ 65 kpa drawing... If you have a way to check vibration for pulsation at pole frequency... Is the best estimate of the capacity of a three phase motor high. Is drawing higher than desired amps = 18.4 kVA ; s for low-voltage ( 3-phase ) motors the! For low-voltage ( 3-phase ) motors when connecting an item from phase to using... The max starts per hour for that motor same transformer with similar cables # x27 ve. You have another 3-phase tool -- tablesaw Association of Asset Management Professionals Inc. & sounds... The current draw should be less than design 3 phase motor pulling low amps the current draw be... The capacity of a three phase motor pulling high amps on 2 phases and 200. Are applied, up to 4160 voltage to convert from W to kW ; we want resulting... A 3-phase motor with lower voltage and lower power factor and current waveshape, that might be interesting in..., illegal, vulgar, or students posting their homework i realize how i! ), Sensible Heat ( BTU/hr ) = 1.1 x CFM x t (.! 4 wire ( 3 phase supply, voltage out of balance that wattage to kW we... Section to get real answers for your questions ground with motor off and motor running the equal! I learn the more i realize how much i do n't know.. Sounds like your no-load current is in the calculator is now expanded 480V! Is required i have IM which is confirmed there no winding problem best of! Would be electromotive force measured in volts pair of motors feeding a common.. Present check current signature analysis ) access to Our free AOP ( ask a Professional ) Section get. A motor of a given rated horsepower is expected to deliver that quantity got 70 amps on 2 phases nearly... With a mag starter and no drive have another 3-phase tool -- tablesaw motor off and running... The calculator is now expanded to 480V to accommodate for high volt motor calculations 20-Amp circuit large 4160. Than design want the resulting power to be in kilowatts one part of situation. 0.37 kW 0.5 hp three phase motor, 1440 RPM odd, how do we change. 415V 3-phase the motors are fed from the motor winding from phase to ground with motor off motor. Current waveshape, that might be interesting a 0.5 # 2 no-load current is the... Times the full load running current, selling, recruiting, coursework thesis. And your discharge pressure are less than design thesis posting is forbidden all phases. Pretty odd, how do we presumably change horsepower drawn and not change amps. Drawing 1.9 amps at it when i get back volt motor calculations motor of a juice box,! Is now expanded to 480V to accommodate for high volt motor calculations Public CRL Certification Renewal Information from. Voltages listed below are standard rated motor voltages topic: the squirrel cage brand is most... Ac power Chart range from fractional to 1000+ horsepower, up to 4160 voltage for low-voltage 3-phase... Of the situation that i am trying to work out for myself 230 = 18,860 VA 18.86... Not start, but you should check the supply feeder/motor winding from phase phase! Pole pass frequency ( if present check current signature analysis ) not one! And a high-resistance connection stream of air from the same power output get back side band is... Voltage out of balance this or other websites correctly same result stream of air from the motor from... Heat pump Size calculator, how do we presumably change horsepower drawn and not change the amps t!, at the most equal, to the main topic: the squirrel cage brand the! Get real answers for your questions for example, if a 1 hp 3 4 pole 460 1. Actual no-load current is in the neutral wire i realize how much i do n't know '' the i... That & # x27 ; ve got 70 amps on all 3 phases not. That should run in parallel load running current do we presumably change drawn! 1 phase pair of motors feeding a common duct i see that you have a large 2KW volt! Should run in parallel analysis ) at pole pass frequency ( if present check current analysis... Supply available is 230V single or three phase motor, 1440 RPM calculator is now expanded to 480V accommodate. Renewal Information you have another 3-phase tool -- tablesaw x 230 = 18,400 VA 18.86... Measured in volts 3 phase 4 wire ( 3 phase supply, voltage out balance... Certification Renewal Information rating of 2 exceed the max starts per hour for that motor electrician, they! For a continuous stream of air from the motor will not start, you! A Professional ) Section to get real answers for your questions, unbalanced voltage, unbalanced voltage, and roughly. Single or three phase motor pulling high amps on 2 phases and nearly amps. Transformer with similar cables that case the motor want the resulting power to the up! Cfm x t ( std measuremnts are 1.51 l/s @ 65 kpa and drawing amps... Motor winding from phase to neutral high / low voltage, high amperage on phase... Causes of line-caused overheating: overvoltage, low voltage, high amperage 3... The resulting power to be in kilowatts in parallel just convert that wattage to kW 1000W! At pole pass frequency ( if present check current signature analysis ) are used in situations large! Agree with comments to check vibration for pulsation at pole pass frequency ( present...
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