Varian 969-9840, Instruction Manual

Page: 13 / 18

SECTION IV - MAINTENANCE
87-900-865-01 ( B ) 8
4-1 General
Replacement controllers are available on an advance
exchange basis through Varian. If necessary,
information is provided to aid the operator in
determining malfunctions and corrective steps to be
taken.
!
Voltages developed in the unit are dangerous and may
be fatal. Service must be performed by authorized
personnel only.
4-2 Controller test
a) Equipment required
– Digital voltmeter (DVM) true RMS.
– Dummy load: 3 x 48
Ω
, 50W each or 3 x 78
Ω
, 50W
each.
– Potentiometer 50K
Ω
,
1
/
4
W minimum.
b) Test set up
– Remove the power cable.
– Disconnect the Turbo-V controller.
– Set potentiometer to 30K
Ω
and connect it as
directed in Fig. 4-1.
Figure 4-1 – Dummy load connections
4-2.1 Power supply test
a) DC voltage test
Check the DC voltages referring to test points indicated
in Fig. 4-2. Refer also to Figg. 4-3 and 4-4. The meter
should read:
– + 5Vdc ± 5%
– ± 12 Vdc ± 5%
– Ground reference = case of Q3.
Switch on the controller and check:
– 54 Vdc ± 10% between TP3(-) a TP5(+) (Fig. 4-2).
b) AC three-phase output voltage test
On the pump connector connect the DVM in turn
between:
pins B and C, B and D, C and D.
The meter should read 44 Vac ±15%; a different value
of 0.4 Vac is tolerable between phase and phase.
4-2.2 Test with dummy load
– Connect the 48
Ω
or the 78
Ω
dummy loads to the
pump connector pins B, C, D as shown in Fig. 4-1.
– Disconnect the potentiometer, set it to 10K
Ω
, and
then reconnect it.
– Connect the power cable.
– Switch on the controller and check the values as
per he following table.
WARNING!