UPS for 400 Vac Grid, User Guide, doc. rev. 4
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The advantage of operating a UPS in ECO mode is that, in effect, the UPS operates as a stand-by
UPS, not making use of the rectifier and the inverter most of the time, aside from possibly
charging the batteries. In ECO mode the UPS can provide a cost savings of at least 2 or 3 percent
of power consumption.
4.5.
(Optional) Maintenance Bypass mode
There may be occasions when your site's power engineer needs to perform maintenance on the
UPS but does not want to risk the possibility of disturbing or unintentionally disconnecting the
load. The Maintenance Bypass function routes the load power completely around the UPS,
eliminating the technician's exposure to live power.
Depending on your site setup, without Maintenance Bypass mode, safe maintenance procedures
may require an interruption of the power to the load.
Maintenance Bypass breakers must be fitted with a normally open aux contact that
is wired to the forced bypass terminal to ensure the system is on bypass during
transfer to Maintenance Bypass mode.
