Troubleshooting & Repair

Model GFC7001E Carbon Dioxide Analyzer

13.5.5.RELAY BOARD

The relay board PCA (P/N 04135) can be most easily checked by observing the condition of the its status LED’s on the relay board, as described in Section 13.1.4.3, and the associated output when toggled on and off through signal I/O function in the diagnostic menu, see Section 13.1.3.

1.If the front panel display responds to key presses and D1 on the relay board is NOT flashing then either the wiring between the Keyboard and the relay board is bad, or the relay board is bad.

2.If D1 on the relay board is flashing and the status indicator for the output in question (heater power, valve drive, etc.) toggles properly using the signal I/O function, then the associated control device on the relay board is bad.

Several of the control devices are in sockets and can be easily replaced.

The table below lists the control device associated with a particular function:

Table 13-8: Relay Board Control Devices

FUNCTION

CONTROL

DEVICE

 

Wheel Heater

K1

Bench Heater

K2

Spare AC Control

K3

 

 

IZS Valves

U4

 

 

IR Source Drive

U5

 

 

IN SOCKET

Yes

Yes

Yes

Yes

No

The IR source drive output can be verified by measuring the voltage at J16 with the IR source disconnected. It should be 11.5± 0.5 VDC.

Teledyne Analytical Instruments

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Teledyne GFC 7001EM operation manual Relay Board Control Devices, Function Control Device, Socket