Thermal Overload Setting for 11kV Chiller Motors 895KW DOL Start CT Ratio 200/1

Motor Protective Settings

Overload relay setting and calculation - Electrical Engineering Centre

Even easier...

1. Read motor nameplate for the FLA value

2. Read instructions for your specific OL protective device to see how you set it.

You cannot generically assume anything, each relay manufacturer has their own internal design philosophy. OL relays have a "pick-up point" at which the relay begins to respond to the motor OL condition. Depending on the regulations in different parts of the world, that pick-up point is going to be anywhere from 115% to 125% of the motor FLA. In addition, some relay mfrs expect YOU to factor in the pick-up point, others do it for you, meaning you set the relay AT the motor FLA. Without knowing what yours does, you cannot assume. Assuming is guessing, and on something that big, guessing wrong is going to be very expensive.

For such high powered motors relay setting has to perfect.For this one has to study the motor characterstics like, Fulload current, starting current, acceleration time, time constant, no of starts , cold and hot withstand time etc.

Only with these information correct setting can be proposed.

This assumes you have a relay that is capable of this level of programmability. The OP made no mention of what he/she has...

Although he has not mentioned, such motor protection relay required for these type of high powered motors.

Please find attached Motor Data Sheet, We are using Sepam 40 Motor Protection Relay, Please advice !!

Embedding a temperature sensor in the motor windings might be a good idea, too.

A phone call to the motor manufacturer is overdue, if the information is not already contained within the data sheet for the particular motor. With regard to the latter, it cannot be seen from here.

Try this.. go to your office, pick up the phone and call someone who knows what they are doing!

See-for instance:

IEEE 242/2001 ch.10.5 Medium-voltage motor protection

and

XM1 - Motor protection relay

file:///C:/Users/user/Downloads/proddocspdf_2_354.pdf

At first it is impossible to read the attached list.

If the stall time is 10 sec you have to check if the starting time it will be less.

You need the compressor inertia moment and to state if the start will be at no-load or not.

See ABB instructions how to appreciate the starting time.

See Sepam 40 instructions :

http://www.engineering.schneider-electric.se/Attachments/ed/use_main/sepam_40_user_manual.pdf.pdf

Try to contact Schneider Electric at your country.