Motor temperature monitor

[CharlesHeraver]

Greetings,

I am looking for a temperature monitor. It needs to monitor (8) 10 ohm copper (Cu427) RTDs in a 3 phase 480VAC motor.
We currently use Chromalox 3421 monitors, but these are 15+ years old and past their prime.

I have found several units on line, but I am wondering if anyone here can say anything good or bad about monitors they have in use.

Thank you very much.

Charles Heraver
Instrument Technician
Central Lake County joint Action Water Agency
200 Rockland Road
Lake Bluff, IL 60044

charles@clcjawa.com

 

[jraef]

You have 2 ways to go.

1) I would recommend that if your temperature monitor is that old, it's likely that your overload protection is that old as well. A good Motor Protection Relay is the best way to go for this, and several of them can accept that many RTD inputs. That way, the Motor Protection Thermal Image is biased by the actual temperature readings. You also get the ability to do hot spot monitoring, voting, RTD failure etc. Choices: GE/Multilin (469) and Schweitzer are the best products out there in wide use.

2) A separate RTD relay to just replace what you have. Some of them use a mux to cycle through multiple RTD inputs so they are not as comprehensive as the MPRs above, but will serve your basic purpose. The two I know of are Solcon and Springer Controls, although it looks as though the Springer version may not accept 10 ohm copper.


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