MGE UPS Systems EPS 7000 user manual Uninterrupted Transfer Conditions

Models: EPS 7000

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EPS 7000 Single Module

3.Wait for the green LED “B” on the hidden panel to turn on (indicating that the rectifier/battery charger has started), then close the battery disconnect circuit breaker QF1. If there is more than one battery cabinet in your configuration, close all the battery disconnect circuit breakers.

4.Automatic restart of the UPS is the normal configuration; the UPS inverter will start automatically and resume normal operation. If your EPS 7000 has been programmed NOT to automatically restart, start the inverter by pressing the “inverter on” pushbutton on the UPS front panel. In a few moments, the inverter will start and the UPS will resume normal operation. If the transfer conditions are not satisfied (bypass out of tolerance or other reason), a forced transfer will be required. Refer to section 2.12, Forced Transfers.

2.12Forced Transfers

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

CAUTION:

Opening Q4S with the inverter stopped in a UPS without

 

maintenance bypass will disconnect the attached load.

 

 

 

 

2.12.1Uninterrupted Transfer Conditions

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.

2.12.2Forced Transfer from Bypass AC Input Source to Inverter

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.

2.12.3Forced Transfer from Inverter to Bypass AC Input

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.

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Operation

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MGE UPS Systems EPS 7000 Uninterrupted Transfer Conditions, Forced Transfer from Bypass AC Input Source to Inverter