Western Instruments Yoke WC-42 - Power Cord Trouble Shooting
WC-Series Yokes use the Omron B3F Series switch. These switches have a ground
provision, are designed for rugged use, and are sealed. Additionally, these switches
conduct less than ½ Watt of power, and are connected to our solid state switching
module. WC switches are therefore unlikely to fail. There is, however, the chance
that an electrical overload or mechanical damage may occur. These instructions can
be used for all manufactured products that use the Omron B3F series switch.
1. Remove the switch cover. WC series yoke switch covers are glued in
position to create a water resistant seal. Prying the switch cover off will
damage the material, but it is prudent to replace the switch cover when
repairing the switch.
Using whatever tools at your disposal, the old switch cover must be
removed, without damaging the switch cavity or the cast in Cover Seat
that the switch cover sits on. Furthermore, it is better to remove the old
glue as well.
Note: If the underside of the switch cover is burned, it is a telltale sign that
the yoke has been connected to 110 volts DC. This power is found on old
engine driven portable welders and some merchant ships.
2. Using a pair of tweezers or small pliers, gently lift the switch up out of the
cavity without damaging the 3 wires that are soldered to it. Note the
positions of the wires on the switch. When replacing the switch, the wires
must be soldered in the same positions. Refer to Testing WC-Series
Frame write up for the identification of wires on the Junction Tubes
Connector.
3. Using the tweezers or pliers, hold the switch, then apply heat with your
soldering iron. The switch is then easily removed and the switch wires are
pre-tinned. Take care not to touch the encapsulant with the soldering iron.
4. Examine the switch cavity. Note any burns that would indicate a use of
DC voltage.
WC-Series
Switch Cavity
Switch Cover Seat
Ground Wire
2nd Connector on Junction
Tube Connector (Common)
3rd Connector on
Junction Tube
Connector (Live)
Distributed by: ABQ Industrial LP USA
Tel: +1 (281) 516-9292 / (888) 275-5772 eFax: +1 (866) 234-0451
Distributed by: ABQ Industrial LP USA
Tel: +1 (281) 516-9292 / (888) 275-5772 eFax: +1 (866) 234-0451
