What is the formula to calculate the rating of a thermal
over load relay

Answer Posted / jayakumar.k

There is no General formula .but the general practice is
motor FLC should be the setting . for e.g 3.7 kw motor the
FLC is 8 amps. we can select the relay 6A-10A range. 8Amps
shoud be the trip setting.

Is This Answer Correct ?    25 Yes 17 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

which model T or pie model is prefarable in power syatem

1424


What is the tension required for the 25000 CFM AHU belt

2053


In EDO ACBs what is a purpose of closing coil and motor, what is the operation of these devices are they inetconnected. means if we give supply to motor and by BCS we charge Closing coil,what exact is operation is and how it charge a spring of ACB. Sir if anybody has an wiring diagram please send me the link to operate and EDO breaker.

1630


What is the voltage gain or transfer function of amplifier?

695


What is the efficiency during maximum power transfer?

685






I have 440v power coming to facility,( not being used ) can I buy large generator, (gas) to sell power back to electrical co.

2020


Can i replace Earth leakage relay to the faulty Earth Faulty Relay

1043


Assuming that a dedicated neutral earthing transformer is provided for each GT generator, when the two generators are running in parallel, has consideration been given that the earth fault current from one generator stator winding be split between the two neutral earthing transformers? If so, what adverse impact will this have on the operation of the 59N and 27TN devices?

1233


I need bhel electrical test pattern & paper

1396


With a phasor diagram show the effect of increasing the field current of a generator supplying a constant real power and connected to a grid system.

1512


1. Can a 12v DC choke operate a 60v/12w PL lamp ? 2. Can a 230v ballast fire / operate a 60v/12w PL lamps.

1762


What is DC series motor?

724


63MVA,220KV/6.9KV Transformer LV side neutral is connected to Earth pit through NGR. Whether this earth pit required to connect with near by below grouding earth mat or it is to be kept separate?

2298


specify the inbuilt protections in DG

1616


Please elaborate th´evenin’s theorem?

692