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ROC800-Series Instruction Manual

Revised Jul-14

Inputs and Outputs

6-13

Caution

Failure to exercise proper electrostatic discharge precautions, such as

wearing a grounded wrist strap may reset the processor or damage

electronic components, resulting in interrupted operations.

To test the thermocouple module:

1.

Disconnect the thermocouple from the thermocouple module.

2.

Generate the correct J or K signal using a multimeter and connect the

wiring from the multimeter to the T/C module.

3.

Verify the ROC is reading the generated temperature from the

multimeter.

4.

Remove the test equipment, and reconnect the field device.

To test the thermocouple:

1.

Disconnect the thermocouple from the ROC800.

2.

Connect the thermocouple directly to the multimeter and verify the

reading is correct by comparing it to a certified temperature

measurement device connected to the process temperature the T/C is

measuring.

3.

Remove the test equipment, and reconnect the field device.

Unintentional thermocouple junctions cause many measurement errors.

Remember that any junction of two different metals will cause a

thermocouple junction. To increase the length of the leads from the

thermocouple, use the correct type of thermocouple extension wire. Any

connector must be made of the correct thermocouple material and correct

polarity must be observed.

If the reading is

off

:

1.

The type J or K thermocouples are selected on a per channel basis on

the thermocouple module. Verify each channel on the ROC800 and

make sure it is set for the type of thermocouple that you are using.

2.

Ensure any plugs, sockets, or terminal blocks used to connect the

extension wire are made from the same metals as the thermocouples

and correct polarity is observed.

3.

Verify all connections are tight.

4.

Verify the thermocouples have the correct construction (ungrounded)

and are not grounded by other means.

5.

Verify you are using the correct thermocouple wire all the way from

the thermocouple to the ROC800 with minimal connections.

6.

Verify the wiring run is adequately protected from noise.

7.

Test the thermocouple reading from the thermocouple to a meter, and

then generate a signal into the ROC800 as described previously.