GE Industrial Solutions LP11 924 Series 6 & 10 kVA - Manual (Page 28)

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OPM_LPU_11U_6K0_10K_1US_V010.Doc 27 User manual LP11 924 6 & 10 kVA UPS 1.0
4.5.6.3 - NOTES CONCERNING USE / MAINTENANCE OF A PARALLEL SYSTEM
ECO-mode:
If UPS are operating in parallel, the ECO-mode feature is not available.
No-load shutdown:
If UPS are operating in parallel, the no-load shutdown function is not available.
Manual bypass:
CAUTION
If you want to switch one of the UPSs to bypass operation using the manual bypass switch (switch is
turned into position ‘2’) then all UPSs in the parallel system have to be switched to bypass operation in
order to prevent damage.
Shutdown and maintenance:
NOTE
Refer maintenance to qualified and skilled personnel only.
Refer to section 1.3 for further details.
Determine whether UPS # will
- just be electrically isolated (procedure a) or
- physically removed (procedure b).
Procedure a: isolation of a unit (‘UPS #’) from the parallel system
1. A manual transfer to the bypass supply may be required. Ensure that on each unit of the system:
- the circuit breaker ‘bypass on/off’ (9 in figure 19) is in position 'on'
- the LCD screen shows the default screen
- the LCD screen does not show any alarm concerning bypass availability.
2. Determine whether or not the system is redundant, i.e. will the system be able to supply the current load if UPS # is
removed?
2a System is not redundant:
- turn the manual bypass switch of all units into position '2'. Proceed with step 3.
2b System is redundant:
- proceed with step 3.
3. Switch off UPS # with the on/off switch.
Switches (utility, bypass, on/off) of the remaining UPSs in the parallel system should remain in the “on” position.
4. Remove the input fuse from the input of UPS # (F1-4 in figure 17).
5. Separate the output of UPS # from the output junction (S1-4 in figure 17).
Do not disconnect the network cable(s) and/or bus terminator!
6. The unit is now electrically isolated from the parallel system.
Have maintenance work performed by qualified service personnel only.
To re-enter UPS # into the system:
1. Reinstall the input fuse F #.
2. Close switch S # to connect the output of UPS # to the output junction.
3. Turn switch ‘UPS on/off’ into position ‘on’.
4. If applicable: turn the manual bypass switches of all units back into position ‘1’.