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hello every body...

I'm looking for a Temperature meter to monitor un-attended substations temperature and report an alarm (o/p contact) to the dispature when temp. exceed a Certain degree. this signal will be connected to substation RTU.

specifications:
Operating voltage range 90-130 VDC
Ambient temperature -10°C ~ 55°C.
Meter alarm point Configurable

any suggestion about a such meter will be Appreciated.
thanks

Any conventional temperature transmitter can be used this way. Just buy one with an alarm contact closure. Moore Industries, Emerson, ABB, Honeywell, SMAR, Wika, Yokogawa, and a bunchaton of other vendors make them.

Walt Boyes
Editor in Chief
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Mailto:wboyes [at] putman.net
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Walts suggestions are good if you have a local PLC with analog input or need to monitor the temperature remotely. If you just need a digital point I suggest an indicator with alarm with an RTD sensor:

http://www.predig.com/pd560/index.php

This would give you local indication of temperature and set-point with a contact for remote monitor. There are hundreds of similar units, the PD560 is just one I have used recently.

Roy

It sounds like you're looking for an "ambient temperature alarm" for your box or panel. You've got at least several options depending on the system architecture you choose. See below for a handful of various Acromag solutions.

1. Temperature Limit Alarm Unit (ie; TC to Relay output). Check out Acromag's Model 801A-0200-C. With a TC input option, all you need to do is install a jumper on the TC input terminals and the device becomes an "ambient temperature monitor" in your box or panel. With a "jumped" TC input, the amplifier will be reading the local cold junction compensation (cjc) sensor which is effectively an ambient temperature monitor. Otherwise, this device does supports TC or RTD temperature sensor inputs if needed.

a. Link: http://www.acromag.com/parts.cfm?model_ID=64&Product_Function_ID=1 3&Category_ID=9&Group_ID=2

b. For 105-130Vdc power, you can use a Universal Power Supply w/ 24Vdc output. See Model PS5R-B24.

Link: http://www.acromag.com/parts.cfm?Model_ID=230&Product_Function_ID= 20&Category_ID=12&Group_ID=2

2. Temperature Transmitter (ie; TC to 4-20mA). With this TC solution, you would feed the 4-20mA into a local controller for temperature monitoring and alarming. Check out Acromag's Model 655T-0600. This is a 24Vdc loop powered device that could be powered from a Sourced 4-20mA AI card or a separate power supply as referred above.

a. Link: http://www.acromag.com/parts.cfm?Model_ID=56&Product_Function_ID=1 3&Category_ID=8&Group_ID=2

3. Panel Meter TC/RTD inputs and relay outputs as Walt Suggested.
Acromag offers Model APM765-6R2-00 which includes 90-265Vdc power option and 2 relay outputs. It supports TC and RTD inputs.

a. Link: http://www.acromag.com/parts.cfm?Model_ID=322&Product_Function_ID= 43&Category_ID=23&Group_ID=2

4. Thermocouple Remote I/O via RS485 Modbus RTU or Ethernet Modbus TCP/IP protocol back to your controller. If you controller supports these protocols, you can consider polling the devices and providing local alarms. Check out Acromag's Model 924MB-0900 (TC input w/RS485 Modbus RTU output) or Model 965EN-4004 (TC input w/Ethernet MB TCP/IP output). These are 24Vdc powered and would need to be used with a universal power supply as mentioned above.

a. 924MB (RS485 MB RTU)
Link: http://www.acromag.com/parts.cfm?Model_ID=89&Product_Function_ID=1 3&Category_ID=9&Group_ID=2

b. 965EN (Ethernet MB TCP/IP)
Link: http://www.acromag.com/parts.cfm?Model_ID=304&Product_Function_ID= 28&Category_ID=22&Group_ID=2

If you have any questions, please feel free to email me.

Kind Regards
Donald Lupo (dlupo [at] acromag.com)

Hi,

You can use a Dial Thermometer with a Switching Capability. With this, you can apply the Setpoints for Alarm and Trip to be used as Binary Signals to your PLC.

Regards, Ramu