Liebert NX 30 User Manual

54 User Manual 10H52192UM60 - Rev. 1 - 09/2011
Liebert NX Service
Chapter 7 Service
This chapter covers UPS servicing, including the service procedures for the power module and bypass modules and the replacement
procedure for the air filters.
Warning: Hazardous mains and/or battery voltage present behind protective cover
1. The components that can only be accessed by opening the protective cover with tools may not be operated by the user. Only
qualified service personnel are authorized to remove such covers.
2. When performing maintenance work on the UPS, note that the neutral line is energized.
7.1 Service Procedures for Power Module and Bypass Module
7.1.1 Notes
1. Only customer service engineers may service the power and bypass modules.
2. Remove the power modules and bypass module from top to bottom to prevent the cabinet tipping over due to the high center of
gravity.
3. To ensure safety, before servicing the power modules and bypass module, be sure to use a multimeter to verify that the DC bus
capacitor voltage is lower than 60 Vdc, and that the voltages between the earth and the components you are going to work on are
below hazardous levels, i.e. lower than 60 Vdc or 42.4 Vac peak value.
4. The bypass module cannot be swapped. Only when the UPS is transferred to internal or external maintenance bypass or
completely powered down can the bypass module be removed.
5. After the power modules and bypass module have been removed, wait 10 minutes before servicing them.
7.1.2 Service Procedure for Power Modules
Provided that the UPS is in normal mode and that the bypass is normal:
1. If the available UPS power modules have redundancy, proceed to step 2; if not, press and hold the INVERTER OFF button on the
operator control and display panel for two seconds to manually turn off the inverters; the UPS transfers to bypass mode.
2. Set the Ready switch on the front panel of the power module to the up position (i.e. in unready state).
3. Two minutes later, remove the fixing screws on both sides of the front panel of the module and pull the module out of the
cabinet.
Note
The module will be blocked by a spring bolt located on the left side of the module when the module is pulled halfway out of the cabinet.
At this point, you must press the spring bolt before continuing to pull the module out.
4. After servicing the module, check that the address of this module is different from those of other modules and that the address is
in the range from one to five (one to six for 200 kVA UPS). Check that the Ready switch is in the unready state.
5. Insert the module into the cabinet (after at least another 10 seconds) and tighten the screws on both sides.
6. Wait for two minutes and then set the Ready switch on the module to the down position; the module will connect to the system.
If the UPS has been transferred to bypass, press and hold the INVERTER ON button for two seconds to start all the power modules.
7.1.3 Service Procedure for Bypass Module
Provided that the UPS is in normal mode and that the bypass is normal:
1. Press and hold the INVERTER OFF button on the operator control and display panel for two seconds to manually turn off the
inverters; the UPS transfers to bypass mode.
2. Close the maintenance bypass switch QS3; the UPS transfers to maintenance mode.
3. Open the internal and/or external battery circuit breakers (internal QS6 and QS7).
4. Open the UPS output switch QS4 and the input switches QS1 and QS2.
5. Remove the fixing screws on both sides of the front panel of the bypass module and pull the module out of the cabinet. Wait for
10 minutes before servicing the bypass module.
6. After servicing the module, insert the module into the cabinet (after at least another 10 seconds) and tighten the screws on both
sides.

Liebert NX 30 Specifications

General

Brand	Liebert
Model	NX 30
Category	Power Supply
Language	English