User guide

TS 870 TRANSFER SWITCH
PM062 REV 5 08/05/05 15 Thomson Technology
7. GENERAL NOTES ON SERVICING TRANSFER SWITCH
MECHANISM
DANGER!!!!
Arc Flash and Shock Hazard. Will cause severe injury or death.
Do not open equipment until ALL power sources are disconnected
This equipment must be installed and serviced only by qualified electrical
personnel utilizing safe work practices and appropriate Personal Protective
Equipment (PPE). Failure to do so may cause personal injury or death
Note: Refer to product drawings in sections 12, 13 & 14 for identification of Transfer Switch
Mechanism style supplied with the Transfer Switch.
When performing any service work on the transfer mechanism, it is imperative that the following be
observed:
7.1. To maintain mechanical integrity, ensure that:
• On T Style mechanisms, all limit switches are correctly adjusted to provide full
travel of the power switching device toggles without exerting unnecessary forces
associated with excessive travel. Ensure that power switching device travel far
enough to reset any internal trip unit (it is more important for the toggle to go fully
in the "off" direction, than in the "on" direction).
• Mechanical interlocking is correct when one power switching opens well before
the other should close.
• All fasteners are adequately tightened.
• The operating linkages are not damaged or bent, and that all bearing points
operate freely.
• On S style transfer switch mechanisms, check nylock nuts on bolt pivot points.
Operation arms should move freely without excessive play.
7.2. To maintain electrical integrity, ensure that:
• All electrical connections, especially power connections, are clean and
adequately tightened. Corroded or loose power connections will cause
destructive heating, and may cause premature tripping.
• All insulating devices are in place and in good condition.