OPTI-UPS DS120KC33 - Manual (Page 34)

After wiring, please check the following points listed below.
(1) Screws in each point are tight.
(2) Ground wire is connected well.
(3) No short-circuit in the output switch board and load circuits.
(4) Battery fuse switch S4 in switched off.
(5) Batteries are connected correctly.
(6) All switches of the UPS from S1 to S6 are off.
4-2-4 Precaution for grounding system
The grounding mode is divided into 4 categories:
(1) Equipment grounding: used in low voltage equipment, grounding by non-charged metal.
(2) Internal wire system grounding: internal wire inside UPS cubicle which connects to equipment
grounding.
(3) Low voltage power system grounding: grounding the secondary winding neutral wire of the
transformer.
(4) Equipment and system grounding: use the same grounding wire to connect the internal wire
grounding and equipment grounding to the same point.
4-2-5 Precautions for connecting batteries
(1) For safety, technician should put on insulating glove when handling or installing the UPS.
(2) Before removing the UPS, be sure to check if the grounding wire is connected tightly and keep
hands and legs dry. Then cut off battery circuit from the equipment.
(3) When removing battery, remove first terminal B+ and B- in the UPS, then remove the wire
connecting the different battery layers.
(4) When removing connections between batteries, pay attention no to touch the neighboring
battery terminal to avoid short cut.
(5) When mounting batteries, assemble separately the battery set in each layer, and then connect the
different layers and finally connect B+ and B- terminal to the battery breaker.
(6) After installation of the batteries, check if the voltages polarity on the battery circuit breaker is
correct.