MT motor Power consumption measurement

[BenEng31]

Hello Gents,
I have an MT motor (5,5KV,955KW) I need to measure the power consumption online using a TC/TP to get a 4-20mA signal to use it in the anti-surge contol loop , How I can choose those transformer ? can you help please .Thank you

 

[zcut123]

check this acuvim meter, it might help

http://www.powermeterstore.com/p8161/acuvim_kl.php

 

[DRWeig]

Acuvim is good. You can also check Kele, Veris, E-mon, Honeywell, and a number of others. If you call or e-mail them with your application, they'll help you select the right current and potential transformers to go with their meter equipment.

Disclosure: I am a consultant for Kele.



Best to you,

Goober Dave

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[jraef]

What are you using to protect that motor? If you have a modern Motor Protection Relay, chances are it has an analog output, or an option card for one, that will give you what you want. Most also have the ability to communicate to higher level systems, a few even now come with and Ethernet port that you can access via a built-in web page.

If you are not using an MPR, why not? Protecting your very expensive Medium Voltage machine and the down time it can represent, using the cheapest and thereby the least function protection equipment, is not considered Best Practice in most engineering circles. Maybe it's time to think about upgrading.


"Will work for salami"

 

[BenEng31]

Hello gents,

Thank for clarification, my probleme is how to select the good TC and the good TP for this motor , for monitoring the solution existe M2M from ABB or others .
Thank for reply

 

[DRWeig]

Well, if your power meter with the 4-20 mA output you want has these specifications:

Voltage sensing inputs: 120V
Current sensing inputs: 0-5A

You will need a 3-phase 5500/120 PT and a set of three 100:5 CTs.

The easiest answer, though, is to ask the people who sell the power transducer, they will help you choose a PT and some CTs to go with their transducer. Not all of them work on 120V and 5A.

If this is not what you are looking for, we'll need more clarification.

If our confusion is because English is not your first language, you might try posting in the Translation Assistance for Engineers forum. If English is your primary language, please red-flag my post and pardon me!

Best to you,

Goober Dave

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[BenEng31]

Hello evrybody ,
Dear DRWeig, thank you for the clarification, you are right , the English it is not my mother language , for that may they have some confusion in my question.

I need to find 3-phase 5500/120 PT and 3 100:5 CTs, are there any special recommendation to choice those transformers .

Thank you again

 

[DRWeig]

I will defer to the others in this forum. My PT experience is all less than 5 kV. However, I have had good success and reliability with Instrument Transformers, Inc. and they are a division of General Electric. They should be available almost everywherea.

You will need to decide the accuracy you need, and the burden capabilities. A sales engineer or manufacturer's representative can be most helpful.

Best to you,

Goober Dave

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[ScottyUK]

The chances are that the switchboard or MCC will already have a VT on the busbar somewhere, probably at the incomer. If such a VT exists then it would make sense to use it rather than try to retrofit one. Installing an additional CT on modern MV gear is often a relatively straightforward task. In the majority of cases a standard low voltage CT can be used because it is installed on a section of conductor with an earthed screen. If you are uncertain about any of this then please get help from someone who is familiar - MV switchgear isn't forgiving of errors.