Owner`s manual

Inverter rating 3.5 kVA 7 kVA 10.5 kVA 14 kVA 17.5 kVA 21 kVA
DC breaker rating 125A 250A 375A 500A 650A 750A
3.4.2.2 AC Output Circuit Breaker
It is not required, but highly recommended. A power “Distribution” panel is available from MGE UPS Systems at a
nominal cost. Order part number XXXXXXXXX, which will accommodate up to 24 single-pole circuit breakers,
“Square-D” QO type.
3.4.2.3 Cable Connection and Static Switch Module
All input and output connection terminals are mounted inside the built-in “Static Switch”. It is very easy to identify
this module by looking at a front panel that has twin cooling fans. This front panel can be opened with a #2 “Phillips”
screw driver. When making connection, always double check to make sure that DC cable goes to DC bus bars,
identified as (+) and (-). The utility cables go to a terminal block, 120/240VAC connects to TB1-2, NEUTRAL to TB1-4.
AC output is from TB1-1 (120/240VAC), NEUTRAL to TB1-3. One of the best ways to verify continuity is to use a DMM.
3.4.2.4 ON-LINE Mode
ON-LINE mode is the mode in which the load is powered by the invert system, not the utility. It will get clean,
transient free electrical power from the inverter system, which is producing the AC power from a DC power source.
3.4.2.5 OFF-LINE Mode
OFF-LINE mode is the mode in which the load is powered from the Utility power line (external AC input power). In
the event of a power failure, a static transfer switch will connect the system output to the inverter and activate the
inverter so as to provide continuous power to the load with no interruptions of power to the load.
3.4.2.6 Troubleshooting Guide
After having thoroughly reexamined the installation and setup of the system, and still found it un-operational, user
can follow Table 3-2 to identify a problem, its cause, and recommendations for fixing it.
Table 3-2: Troubleshooting
Problem Possible Cause Possible Solution
Display panel not illuminated No power to system Check AC % DC power sources.
No output voltage SW1 not ON Turn SW1 ON
System starts, then shuts Overload, or shorted Remove some of the load and
down almost immediately output. restart the inverter.
Power module LED turn red Module faulted Reset by recycling circuit breaker
Module temp. indicator on Module fan failure Replace module or cooling fan
3.4.2.7 Inverter Configuration
3.4.2.8 Battery Booster
Battery booster is a push-pull type converter on which average current-mode control scheme was employed for
better dynamic response. The circuit utilizes a high frequency transformer for obtaining a pair of +213.5/-213.5Vdc
output and for galvanic isolation as well.
3.5 to 21 kVA N+1 Inverter
Maintenancepage 3 — 4