Operator's Manual

Operator’s Manual ASCO 336 / 337
381333-427 A ASCO Power Technologies Page 5
Functional Test
The functional test consists of three checks: manual
operation, voltage checks, and electrical operation.
Do these checks in the order presented to avoid
damaging the transfer switch.
1 – Manual Operation
A maintenance handle is provided on the transfer switch for
maintenance purposes only. Manual operation of the transfer
switch should be checked before it is energized (before it is
operated electrically). Note the contact position indicators.
Do not manually operate the transfer switch until all
power sources are disconnected: open both
generator circuit breakers and all load circuit
breakers.
Figure 2. J-design transfer switch maintenance handle.
1. After deenergizing both power sources, open the enclosure
door. Locate and remove the maintenance handle. Select
either H-design or G-design. See Figures 2 and 3.
J & H-design see Figures 2 & 3
The maintenance handle is stored in clips on the left side
of the transfer.
G-design see Figure 4
The maintenance handle, hub, and pin are stored on the
center frame of the transfer.
2. Install the handle into the hole in the molded hub. Move
the handle up or down as shown to manually operate the
transfer switch to close and reopen the contacts. It should
operate smoothly without any binding. If it does not, check
for shipping damage or construction debris.
J & H-design see Figures 2 & 3
The transfer switch has two contact shaft hubs Install the
maintenance handle into the hole in the molded hub. The
upper hub operates the Generator 2 contacts. The lower
hub operates the Generator 1 contacts.
G-design see Figure 4
Install the hub (with pin) onto the shaft. Insert the
maintenance handle into the side hole in the hub. Push in
the shaft to operate the Generator 1 contacts. Pull out the
shaft to operate the Generator 2 contacts.
3. After checking manual operation, return all transfer switch
contacts to the open position. Generator 1 and Generator 2
contacts must be open. Check contact position indicators.
4. Remove the maintenance handle and store it on the transfer
switch in the place provided.
J & H-design see Figures 2 & 3
Store the maintenance handle in the clips on the left side of
the transfer.
G-design see Figure 4
Store the maintenance handle, hub, and pin on the center
frame of the transfer.
Note: If Generator 1 and Generator 2 connections are reversed
this operation is also reversed.
Verify that the maintenance handle has been
removed and stored properly before electrically
operating the transfer switch.
NOTIC
E
WARNING
!
WARNING
!
Left side of the
transfer switch
Hubs shown with
Generator 1 source
contacts open and
Generator 2 source
contacts closed.
Maintenance handle
Generator 2
contact shaft hub
Generator 1
contact shaft hub
Clip