Troubleshooting - Siemens OpenAir GCA Series Technical Instructions

Technical Instructions
Document Number 155-173P25
March 17, 2006
5. Check the Auxiliary Switch B:
Start-Up
Commissioning,
GCA15X
GCA16X
Continued—
Special
Modulating 4 to 20 mA control with GCA15x
and an external 499-ohm resistor (985-124,
Application
See Accessories).
NOTE:
Service

Troubleshooting

a. Set the DMM dial to ohms (resistance) or continuity check.
b. Connect wires S4 and S6 to the DMM. The DMM should indicate open circuit or no
resistance.
c. Apply the input signal as in Step 1d, to wire 8 (gray).
The DMM should indicate contact closure as the actuator shaft coupling reaches the
setting of switch B.
d. Connect wires S4 and S5 to the DMM. The DMM should indicate open circuit or no
resistance.
e. Apply the input signal as in Step 1f, to wire 8 (gray).
The DMM should indicate contact closure as the actuator shaft coupling reaches the
setting of switch B.
985-124 is provided with the GCA15x
actuator.
WARNING:
Do not open the actuator. If the actuator is inoperative, replace the unit.
WARNING:
To avoid injury or loss of life, pay attention to any hazardous voltage
(for example, 120 Vac) when performing checks.
•
Check that wires are connected correctly.
•
Check that offset (start point) and span are set correctly, if used.
•
Use a Digital Multimeter (DMM) to verify that the operating voltage is within range.
•
If the actuator is not working, check the damper for blockage. If blocked, remove the
obstacle and cycle the actuator power off and on. The actuator should resume
normal operating mode.
OpenAir GCA Series Spring Return 142 lb-in Electronic Damper Actuators
Supply (+)
Supply
Controller
Control
Signal
4 to 20 mA
1 8
499Ω Supply
Input
Resistor
2 to 10V
Assembly
from Kit
Actuator
985-124
Neutral
2
Neutral (-)
Figure 27.
Wiring Diagram for Converting
4 to 20 mA into 2 to 10 Vdc.
Neutral