5 PT 100 sensors on motor relays

[pisimatza]

Hi.
Can anyone give me the cheapest solution for a digital motor protection relay, with connection possibility for 5 PT 100 sensors ?
I have checked some relays like MM200, MM300 from Multilin, General Electric , but only 1 thermistor imput available.

Motors are 400V AC.

 

[RRaghunath]

Have you tried P225 or P241 of AREVA, both these relays come with 10RTD input option.

 

[jraef]

All of the major manufacturers of Motor Protection Relays have, in their high-end products, options to accept motor RTDs,; either 10 or 12 inputs is common. But they are all going to cost you around $5k US and higher.

For low cost low voltage applications, the Siemens Simocode Motor Management Relay can have an expansion module attached that will accept 3 PT100 RTDs and the base unit will accept 1 additional thermistor, but to do 5 RTDs, you will need a bigger relay.

If all you want are the RTD inputs and you have another SSOL that you can use, there is a straight RTD relay that can accept up to 8 inputs, such as the Springer T-538 relay. I have used them in the past, they work great as long as you don't want high speed sensing. They use a mux to cycle through the probe inputs (and in fact, you also have to be willing to put up with the clicking sound of the mux) and it takes a few seconds for it to cycle though, even if you don't have probes hooked up to all of the inputs.

http://www.springercontrols.com/catalogs/TempContr.Catalog.pdf

If you have something in the control system with Modbus master capability, you can also use the Startco SIO-RTD module.

http://www.startco.ca/products/sio-rtd/

 

[slavag]

In additional to Jraef's list, please see

http://www.solcon.com/Index.asp?ArticleID=36&CategoryID=89

Best Regards.
Slava

 

[slavag]

And of course

http://library.abb.com/global/scot/...3003f59e6/$File/rem610_ANSItob_755723_ena.pdf

motor relay with 6 RTD module

 

[LionelHutz]

You asked for motor protection relay with 5RTD inputs. None of them will be real cheap but there are a few options under $5k as jraef says.

I don't know where you are in the world but Startco (

http://www.startco.ca)

has a MPU-32 motor protection relay that you can add a RTD module to. I think it's a fairly cheap solution.

http://www.selinc.com

has a motor relay and RTD module that runs about $1200 + $800.

 

[pisimatza]

Thank you all. It was important to know that 5k USD is the figure, i found some relays(369 from Multilin, but i thought taht 5 K is a huge figure ).

 

[LionelHutz]

Yes, for what's in a GE Multilin relay I think they're expensive too. GE Multilin must put a lot of gold in their relays or something.

You could possibly buy a whole soft-starter with built-in motor protection (including 8 100ohm RTD) for that $5k (or not too much more) depending on the size of the motor.

 

[jraef]

Excellent point.