Checking Linear Current 0-20 Ma Inputs; Checking Binary Inputs - Trane Tracer MP581 Hardware Installation

CNT-SVN01C-EN
Checking linear current 0–20 mA inputs
To check linear current inputs for proper operation:
1. Make sure that the sensor is connected and powered on.
2. Set the multi-meter to measure Vac, then measure the voltage across
the input at the signal and common screw terminals.
The measured voltage should be less than 0.1 Vac. If the voltage is
greater than this, sensor readings may change erratically.
3. Set the multi-meter to measure mA, then measure the current across
the input at the signal and common screw terminals.
The measured current should be between 0 and 20 mA. If the current
is greater than 20 mA, check the connections at the controller. If the
current is less than 0 mA, check the meter and input connections.
4. Force a change in the sensor reading.
5. Use the multi-meter to confirm that the change appears at the correct
input on the terminal board.

Checking binary inputs

To check binary inputs for proper operation:
1. Make sure that the sensor is connected and powered on.
2. Set the multi-meter to measure Vac, then measure the voltage across
the input connections at the signal and common screw terminals.
The measured voltage should be less than 0.1 Vac. If the voltage is
greater than this, the input readings may change erratically.
3. Set the multi-meter to measure Vdc, then measure the voltage across
the input at the signal and common screw terminals.
The measured voltage should be less than 0.1 Vdc. If the voltage is
greater than this, the input readings may be offset.
CAUTION
Equipment damage!
Continue to step 4 only if you completed steps 2 and 3 successfully.
Measuring resistance may damage the meter if the voltage is too high.
4. Set the multi-meter to measure resistance. If you completed steps 2
and 3 successfully, measure the resistance across the input.
The resistance should be less than 200 Ω when the binary input is
closed and greater than 1 kΩ when it is open.
Checking inputs
31