Emerson Liebert NXL 250 kVA, Operation And Maintenance Manual

Page: 81 / 112

Maintenance
73 Liebert
®
NXL
™
Matching Battery Cabinets—Optional
Although the individual battery cells are sealed (valve-regulated) and require only minimal
maintenance, the Battery Cabinets should be given a periodic inspection and electrical check. Checks
should be performed at least annually to ensure years of trouble-free service.
Voltage Records : With the Battery Cabinet DC circuit breaker closed and the connected UPS
operating, measure and record battery float voltage. With the DC circuit breaker open, measure and
record the nominal (open circuit) voltage. Both these measurements should be made across the final
positive and negative terminal lugs. Compare these values with those shown below. The recorded
nominal voltage should be no less than the value shown; while the recorded float voltage should be
within the range shown. If a discrepancy is found, contact Liebert Services.
Power Connections : Check for corrosion and connection integrity. Inspect wiring for discolored or
cracked insulation. Clean and/or retighten as required. Refer to torque specifications in Table 7 .
Battery Cell Terminals : Check for discoloration, corrosion and connection integrity. Clean and
tighten if necessary. Note that when installing a new battery, the initial torque value is 5 lb.-in. more
than the retorque value. Table 7 shows battery retorque values.
If the system uses a different model battery, contact Liebert Services for the required torque value.
To access battery cell terminals, disconnect the inter-tier cable and two shelf retaining screws. Once
disconnected, insulate (with protective boot or electrical tape) the cables to prevent accidental shorts.
The battery shelf can now be pulled out. Tighten each terminal connection to the retorque value.
When replacing a battery, the terminal connections must be cleaned and tightened. Disconnect and
insulate the cables connected to the battery. Secure each battery shelf with retaining screws when
maintenance is complete.
!
WARNING
Risk of electric shock, explosive reaction, hazardous chemicals and fire. Can cause equipment
damage, personal injury and death.
Do not use equalize charging with valve-regulated, lead-acid batteries. Refer to the battery
manufacturer’s manual, available on the manufacturer’s Web site, for specific information
about equalize charging.
Table 6 Battery voltage, nominal and float
Number of Cells
Battery Voltage, VDC
Nominal Float
240 480 527 - 552
Table 7 Battery retorque values
Battery Mfr. Battery Model # Retorque Value
C&D
UPS12-300MR 110 in-lb
UPS12-350MR 110 in-lb
UPS12-400MR 110 in-lb
UPS12-490MRLP 110 in-lb
UPS12-540MR 110 in-lb
Enersys
HX205-FR 65 in-lb
HX300-FR 65 in-lb
HX330-FR 65 in-lb
HX400-FR 65 in-lb
HX500-FR 65 in-lb
HX540-FR 65 in-lb
16HX800F 100 in-lb
16HX925F 100 in-lb
East Penn
24HR3000 65 in-lb
27HR3500 65 in-lb
31HR4000 65 in-lb
31HR5000 65 in-lb