72 94-1100-00002874 A0 EN│TruFit™ Power Distribution Unit
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7
System maintenance
Minimal periodic maintenance of the unit is required. As with all electrical distribution components, this
system should be regularly inspected for electrical connection integrity, signs of excessive temperature,
accumulation of dirt, and proper system operation.
As with any electronic devices, critical circuits are subject to normal life cycle effects. ABB offers various
service plan levels to keep your equipment in peak operating condition as the unit ages. Contact ABB
Service Sales at ric_servicesales@ us.abb.com or go to https://new.abb.com/ups/service-ups-and-power-
conditioning to learn more.
Only qualified service personnel should perform maintenance on the PDU.
Exercise extreme care to avoid equipment damage or injury to personnel.
Lethal voltages exist inside the unit during normal operation.
7.1
Tightening torques
Recommended tightening torque for all nuts and bolts is listed in the table below. As applicable, torque
seal has been utilized to indicate bolt torqueing.
Table 7-1: Recommended tightening torque
Thread
Size
SAE Grade 5
120,000 psi
Medium Carbon Heat T.
Inch
Lb-ft
N-M
1/4
6
8
5/16
11
15
3/8
20
27
1/2
48
65
All internal bolts are SAE Grade 5.
Note bolt head markings above to distinguish between grades.
All internal machine screws are Grade 2.
