Trane Engineered Smoke Control System, Application Manual

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Checking outputs
BAS-APG001-EN 71
Checking outputs
Follow the procedures in this section to test outputs for proper operation.
IMPORTANT
Perform the tests in this section before providing power to the termina-
tion board or installing the main circuit board. Failure to do so will
result in incorrect multi-meter readings.
To test outputs for proper operation, you need the following tools:
•
Digital multi-meter
•
Small flat-tip screwdriver
Checking binary outputs
To check binary outputs for proper operation:
1. Set the multi-meter to measure Vac, then measure the voltage across
the binary output at the common and signal 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 the
wire to make sure that no additional connections have been made.
•
The wire may have an induced voltage somewhere along its
length.
2. Set the multi-meter to measure Vdc, then measure the voltage across
the binary output at the common and signal screw terminals.
The measured voltage should be less than 0.1 Vdc. If the it is greater
than this, a shared power supply may be incorrectly connected. Check
the wire to make sure that no additional connections have been made.
CAUTION
Equipment damage!
Continue to step 3 only if you completed steps 1 and 2 successfully.
Measuring resistance may damage the meter if the voltage is too high.
3. Set the multi-meter to measure resistance. If you completed steps 1
and 2 successfully, measure the resistance across the binary output to
confirm that there are no shorts and no open circuits.
Resistance is load dependent. Pilot relays have a relatively low resis-
tance of less than 1 k
Ω
, but some actuators have a high resistance.
Check to see what kind of binary output is connected before checking
for open and short circuits.
Checking 0–10 Vdc analog outputs
To check 0–10 Vdc analog outputs for proper operation: