Manual

9. Procedures of DC switch-on:

Activate DC switch-on function set under UPS bypass mode

Make sure that “+”, “-” and “N” wires of batteries are properly connected to UPS

Switch on batteries

Lightly touch ENTER

Manually conduct switch-on order within about 1min after LCD self-inspection

7.2 Parallel machine operation

Redundancy introduction

N+X is currently the most reliable power supply structure, in which N indicates the minimum

UPS number required for the total load and X is the redundant UPS number, namely, the

malfunctioning UPS number that the system can simultaneously bear. The larger X is, the

higher reliability of system will be. For instance, if the total load of a customer registers

55kVA, we can use 20KVA for N+X design. With N taking up 3, X can be selected in ac-

cordance with reliability degree or cost requirement. Supposing customer selects X=2 and

equalized UPS power supply is 11kVA for each unit, when one set of UPS breaks down

with malfunction, the remaining four sets will provide power with almost 14kVA equalized

current; if two sets of UPS fail, the remaining three sets of UPS are supposed to provide

power supply with almost 18kVA equalized current. The maximum allowance of this sys-

tem is for two sets of UPS going down at the same time, the chances of which are much

smaller than those of one UPS malfunction. Therefore, the reliability degree can be largely

enhanced,making it an optimal mode for application in locations where high degree of reli-

ability is always a focus.

PowerWalker VFI 20000TP 3/3 is capable of direct parallel connection, which only requires

the parallel connection wires (optional) for 2 to 8 sets of UPS in parallel connection in order

to realize power redundancy (N+X).

Note!

UPS will be switched off automatically if there is no operation within 1min after LCD

self -inspection is completed!