Installation manual

UT340, UT360, UT380, and UT3100
Planning and Installation Manual
31
2. Switch the maintenance bypass breaker (MBB) “ON.”
3. Switch the UPS output breaker (UOB) “OFF.”
4. Press the red “off” button located inside the UPS front door.
5. Switch the UPS input breaker (UIB) “OFF.”
6. Switch the DC disconnect (DCD) “OFF.”
7. Turn the pre-charge/discharge switch to the discharge position and hold it until the LED
turns off. The UPS display should now be blank.
To restart the unit, see Section 602, “Startup from Maintenance Bypass for Units with a
BEST-Supplied Three-Breaker MBC.”
8. (Optional) If the loads are
not
to be powered, turn off all AC power sources to the UPS
and maintenance bypass cabinet (MBC).
Section 600:Startup from Maintenance Bypass
This section tells how to start the UPS from maintenance bypass. The steps in this procedure are
for a unit with a BEST-supplied maintenance bypass cabinet (MBC).

If you have a unit with a BEST-supplied
rotary switch
MBC, see Section 601.

If you have a unit with a BEST-supplied
three-breaker
MBC, see Section 602.
601 Startup from Maintenance Bypass
for Units with a BEST-Supplied Rotary Switch MBC
1. Make sure that the following switches are in the following positions:

The UPS AC disconnect switch should be “OFF.”

The UPS bypass switch should be on “LINE.”

The DC disconnect (DCD) should be “OFF.”
2. Switch the UPS AC disconnect switch “ON.” The UPS display should show
System
type xxkVA xxxV
and an audible alarm should sound.