Bacharach GDC-150 Manual Do Proprietário
GDC-150 Operation Manual
5209-9000 Rev 0
15
4.5. Open Loop Diagnostic
The GDC-150 circuit board has been fitted with a red LED located near the bottom
center of the circuit board. This is an “open loop” indicator and has been designed as
a quick trouble shooting device. If the 4-20 mA signal loop has not been connected
properly or has been damaged in some manner between the analog transmitter and
the device to which it is sending its signal output, this LED illuminates. At this point,
the wiring should be inspected for potential problems.
center of the circuit board. This is an “open loop” indicator and has been designed as
a quick trouble shooting device. If the 4-20 mA signal loop has not been connected
properly or has been damaged in some manner between the analog transmitter and
the device to which it is sending its signal output, this LED illuminates. At this point,
the wiring should be inspected for potential problems.
4.6. Jumper Functions
Figure 4-1. Jumper Functions
4.7. Adjusting the Alarm Set Point (For Relay Option Only)
If the optional relay has been supplied, the alarm set point on the GDC-150 can be
adjusted. The alarm set point value is converted to a voltage in the range of 0-4 VDC.
This voltage range correlates to the full measurement range of the installed sensor.
adjusted. The alarm set point value is converted to a voltage in the range of 0-4 VDC.
This voltage range correlates to the full measurement range of the installed sensor.
4.7.1. Calculating the Alarm Set Point Value
Prior to adjusting the alarm set point, calculate the voltage value required using the
following formula.
following formula.
Example: Catalytic combustible sensors have a standard measurement range of
0-100% LEL. Therefore 4.0 VDC = 100% LEL. Using the values below, 10% of
4.0 VDC = 0.4 VDC. Therefore, the required voltage setting to achieve an alarm set
point of 10% LEL is 0.4 VDC.