MGE UPS Systems EPS 8000 User Manual

This section describes the normal transfer conditions and the procedures to be followed when issuing forced transfers. 

To transfer the load between the UPS module output and the bypass AC input (mains 2) source without interruption,

the following conditions must be satisfied:

◗

inverter output and bypass AC input phases must be in sync

◗

Bypass AC input voltage must be within 10% of nominal

◗

Bypass AC input frequency must be within a certain programmable tolerance of nominal

Provided that both the UPS module output and bypass AC input sources meet these conditions, uninterrupted

transfers can take place.  If these conditions are not met, transfers cannot take place without interruption.  A forced

transfer is required.

Forced transfers require a power interruption to the load of 0.8 seconds.  Before issuing a forced transfer command,

be certain that the attached load can tolerate the brief outage.  The following paragraphs describe the forced transfer

procedures.

Start the inverter by pressing the “inverter on” button on the front panel.  

On the hidden panel, press the “security” key and hold it while pressing the “forced bypass to inverter” key

(pushbutton #4).  The load will be disconnected for 0.8 seconds, then connected to the inverter.

On the hidden panel, press the “security” key and hold it while pressing the “forced inverter to bypass” key (pushbutton

#5).  The inverter will stop and the load will be disconnected for 0.8 seconds; then the load will be connected to the

bypass AC input source. See Figure 1-10.