Granville-Phillips Mini-Convectron 275 Series, Инструкция по установке, эксплуатации и обслуживанию, Страница: 48 / 52

40 Mini-Convectron
®
Module with DeviceNet
®
Digital Interface
Chapter 6
6.3 Mini-Convectron
Gauge Tube Test and
Replacement This procedure can be used to test and/or replace the gauge tube if you
suspect it has failed.
1. Disconnect the DeviceNet and Trip Point cable connectors.
2. Remove the eight screws holding the two end plates of the module as
shown in Figure 6-1.
3. Remove the one side, front and rear cover plates from the PC board/
gauge tube assembly as shown in Figure 6-1.
4. Hold the PC board/gauge tube assembly and carefully remove the gauge
tube from the tube socket in the direction of the arrow shown in
Figure 6-1.
5. Using a volt/ohm meter, measure the gauge tube pins listed in Table 6-
1 and as shown in Figure 6-3.
Figure 6-3 Mini-Convectron Gauge Tube Pin Identification
WARNING
To prevent electrical shock, shut down electrical power before servicing
the
275 Mini-Convectron Vacuum Gauge Module. Do not touch any
gauge pins while the gauge tube is under vacuum or connected to a
controller.
CAUTION
Make sure the volt/ohm meter being used in this procedure does not apply
more than 10 mA to the gauge tube circuits. Damage to the gauge tube may
result.
Table 6-1 Mini-Convectron Gauge Tube Pin Test Resistance Values
Pins to Test Resistance Values (ohms)
1 to 2 17 to 22.5
3 to 4 27 to 45
2 to 3 45 to 54
1 to 5 180 to 185
1
5
4
2
3