Vertiv Liebert STS2 - Maintenance

Vertiv™ | Liebert® STS2/PDU
™
User Manual | Rev. 6 | 10/2017 145
16.0 MAINTENANCE
Minimal periodic maintenance of the Liebert STS2/PDU is required. As with all electrical distribution
components, the system should be regularly inspected for electrical connection integrity, signs of excessive
temperatures, dirt accumulation and proper system operation.
16.1 Proper Tightening of Nuts and Bolts
The recommended tightening torque for all nuts and bolts is as shown below, unless otherwise labeled. All power
connections are designed to remain at proper torque throughout the lifetime of the unit.
16.2 Testing the Liebert STS2/PDU
The Liebert STS2/PDU includes comprehensive system alarms and fault detection to identify operational
problems. To increase the degree of confidence of proper system operation, periodic transfer tests can be easily
performed. For instructions for changing the preferred source and switching sources, see 10.2 - Manual
Transfer / Preferred Source Selection.
16.3 Changing the Air Filter
A standard furnace filter is installed behind the air intake in the front door. The air intake allows air to circulate to
cool the unit. Replace the filter when it becomes dirty and impedes air flow. The frequency of changing or
cleaning the filter depends on the location in which the unit is located. The size of the filter is 1 x 25 x 25 in. (254
x 635 x 635mm).
WARNING
Risk of electric shock. Can cause injury or death.
Only properly trained and qualified service personnel should perform maintenance on the Liebert
STS2/PDU.
Lethal voltages exist inside the unit during normal operation.
The unit is supplied by multiple AC power sources. Disconnect and lock out all power sources before
working inside unit.
Table 30 Torque tightening
Bolt Shaft Size
Grade 5 - Imperial
Grade 8.8 - Metric
Electrical Connections with Belleville
Washers
in-lb
(pound-inch)
N-m
(Newton-meter)
in-lb
(pound-inch)
N-m
(Newton-meter)
10-32 25 3 35 4
1/4-20 53 6 80 9.0
5/16-18 107 12 180 20.4
3/8-16 192 22 240 27.1
1/2-13 428 48 480 54.3
Table 31 Branch circuit breakers
Current Rating
in-lb
(pound-inch)
N-m
(Newton-meter)
Up to 30 Amp 35 4.0
40 to 100 Amp 45 5.1