Gp 6.13 Contact Blocks - Challenge CMT-130TC Service Manual

GP 6.13 Contact Blocks

This procedure is used to check pushbutton
switch contact blocks for faults. Normally closed
contact blocks have a red actuator, and normally
open contact blocks have a green actuator.
Initial Actions
WARNING
Disconnect and lockout power as described
in the Power Lockout Procedure on page ix.
Procedure
1. Remove the lever lock as shown in Figure
6-16.
2. Rotate the lever from one side of the contact
block to the other in order to release it from
the switch body. Pull the contact block off
the pushbutton body.
3. Make note of where each wire enters the
contact block then disconnect the wires from
the contact block.
4. Press and release the actuator. Does the
actuator return freely?
Y N
The contact block is faulty and should be re-
placed.
Normally Open Contact
5. Check resistance between contact screws.
Is resistance infinite?
Y N
The contact block is faulty and should be re-
placed.
6. Press the actuator and check resistance be-
tween contact screws. Is resistance less
than 2 Ohms?
6. General Procedures/Information
Y N
The contact block is faulty and should be re-
placed.
7. The contact block is good.
8. Re-install switch.
Normally Closed contact
9. Check the resistance between contact
screws. Is resistance less than 2 Ohms?
Y N
The contact block is faulty and should be re-
placed.
10. Press the actuator and check resistance be-
tween contact screws. Is resistance infinite?
Y N
The contact block is faulty and should be re-
placed.
11. The contact block is good.
12. Re-install switch.
MAY 2019
6-14
Figure 6-16. Contact Block
CMT-130TC Book Trimmer