User`s manual
MPS Doc: M359_USER_MANUAL REV J Oct 23, 2014 Page 5 of 30
batteries. Please check your local regulations before disposal.
The Battery Charger is a voltage-regulated and current-limited DC to DC converter. It
is powered from the 270VDC output of the AC-to-DC LID Converter and provides
temperature-compensated float charge to the Battery Pack. This charging method
preserves the batteries and provides the longest batteries-life possible.
The DC-to-AC Inverter generates clean sine-shape 115VAC voltage from the
270VDC output of the AC-to-DC LID Converter. The DC-to-AC Inverter is current-
limited and overload protected. The M359 provides failure isolation between the load
on its output, to the Prime source that feeds the M359. Overloading the UPS output
will not result in an overload on the prime AC source that feeds the M359.
When the UPS is in the By-pass mode, all of its active circuits (including Overload
Protection) are by-passed or disabled. Therefore, overload protection in the By-pass
mode should be provided by the external 32 to 46 Amp circuit breaker (or fuses) at
the AC outlet that feeds the M359 input.
Note: The Power Conditioner contains internal 60Amp fuses on its input.
These internal fuses are intended only as an additional safety feature and
should not be considered or used as the main overload protection devices
.
In the unlikely event that these fuses open, it may indicate the existence of
an internal safety hazard and the M359 should be returned to the
manufacturer for inspection/service. These internal fuses should never be
replaced without through testing of the M359.
The Control Circuit is a microcontroller-based circuit that provides monitoring of the
unit’s status (battery charge, load level, input and output levels, etc.) and supports the
communication and front panel status indicators.
Figure 1, on next page, shows the main functional blocks of the M359. The relays in
Figure 1 are shown in their unenergized state. For simplicity sake, only one pole is
shown for each relay. However, each is a two-pole device that disconnects both of
the AC lines.