American Power Conversion MatrixTM UPS - Manual (Page 7)

3.2 Electronics Unit (EU)
Rear View of the Electronics Unit
1. Electronics Unit (EU)
The Electronics Unit contains the UPS’s microprocessor controls, inverter, battery charger, transfer and tap changing
circuits, remote interfaces, and the user control and display console. The EU may be separated from the IU for service.
See the manual section entitled Difficulty for instructions on removal of the EU.
2. Cooling fans
The EU cooling fans operate at two speeds depending upon mode of operation. The fans turn faster when the UPS is
heavily loaded while operating on-battery. If either of the fans fail while operating on-line, the UPS will indicate an
alarm condition and transfer to bypass operation. It either of the fans fail while operating on-battery, the UPS will
immediately indicate an alarm condition. Initially, the UPS will continue to provide power to the load. However, when
heavily loaded the UPS will eventually shut down in order to prevent the EU from overheating.
3. Battery Pack coupler
Battery Packs are connected at this coupler. A coupler clamp is installed over the coupler opening as furnished from the
factory. See the manual section entitled Installation for instructions on how to lock mated couplers.
4. Accessory panel
The EU is furnished with an opening that accepts accessories that work with the UPS. Call your dealer or the factory for
information on available accessories.
5. Computer interface port
See UPS Monitoring section of this manual for information on this interface port. Connect only factory supplied or
authorized UPS monitoring cables to this port.