3.5
Make the electrical connections
CAUTION
Do not exceed the pressure-switch ratings stated in Section 2. If you do, you can damage
the Exhaust Pressure Module.
Note:
Ensure that when you connect the signals from the pressure-switches to your control equipment,
you do not exceed the switch ratings specified in Section 2. If your control equipment does not
meet the specifications in Section 2, contact your supplier or BOC Edwards for advice.
The 17-way connector on the electrical cable (Figure 6, item 1) is connected to the auxiliary
connector on the back of the Gas Module. A 19-way connector on the front of the Gas Module is
connected to your control equipment.
The Q Series 3 Exhaust Pressure Module uses 8 of the connections in the 17-way connector. These
are detailed in Table 2. Note that the same pin letters are used for these signals on the 19-way
connector from the Gas Module.
Use the procedure below to make the electrical connections:
1.
Pass the electrical cable through the cut-out at the top of the gas services panel on the QDP
pump.
2.
Ensure that the QDP pump is switched off and then plug the 17-way connector at the end of
the electrical cable into the auxiliary connector on the back of the Gas Module.
3.
Connect the signals from the exhaust-purge pressure-switches (which are available on the
19-way connector on the front of the Gas Module) to your control system so that the warning
signal gives an indication that the pressure of the exhaust-purge nitrogen supply is too high
and the over-pressure signal switches off the pump.
12
Q Series 3 Exhaust Pressure Module
Wire number
1
2
3
4
5
6
7
8
Signal
normally closed
normally open
normally closed
normally open
return, exhaust pressure-switch, over-pressure signal
return, exhaust pressure-switch, warning signal
Pin letter
A
B
C
D
E
F
G
H
Table 2 - Electrical connector pin usage (as supplied)
Inlet-purge solenoid-valve
}
}
}
Exhaust pressure-switch
warning signal
Exhaust pressure-switch
over-pressure signal