Checking 0-20 Ma Analog Outputs - Trane Tracer MP581 Hardware Installation

Chapter 5 Wiring inputs and outputs
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Checking 0–20 mA analog outputs
To check 0–20 mA analog outputs for proper operation:
1. Make sure that the actuator is connected but powered off.
2. Set the multi-meter to measure Vac, then measure the voltage across
the analog output 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 load may turn on and off unexpectedly. Check
for the following problems:
A shared power supply may be incorrectly connected. Check along
•
the wire to make sure that no additional connections have been
made.
The wire may have an induced voltage somewhere along its
•
length.
3. Set the multi-meter to measure Vdc, then measure the voltage across
the analog output at the signal and common screw terminals.
The measured voltage should be less than 0.1 Vdc. If the voltage is
greater than this, a shared power supply may be incorrectly con-
nected. Check along the wire to make sure that no additional connec-
tions have been made.
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