Control Signals Overview; Installing Bypass Control Wiring - Eaton 93PR Series User And Installation Manual

4.5.2

Control Signals Overview

Two controls signals (External CAN Network, Bypass Pull-Chain) are required for external paralleling. Both of
these control signals are fault tolerant and alarmed when disconnected.
External CAN (ECAN)
ECAN provides means for communications between the UPS's in a parallel system. The system will continue
to share load and protect the load when this network fails.
Bypass Pull-Chain
Bypass Pull-Chain is an open collector signal that goes low when the Bypass static switch of any UPS is
online. When External CAN (ECAN) is down, the pull-chain is low, and the UPS is online, the UPS will lock to
and transfer to bypass. Service can manually short this signal in some rare failure modes to force a system
transfer to bypass.
Signal Inputs Actions
Each UPS has maximum eight signal inputs, 5 native and one in each Mini-slot when using a suitable
connectivity device. These inputs can be configured with action items. The following action items affect
all UPSs in the system. When an action item is active on a UPS and the MOB is closed, the action item is
transmitted on the ECAN to all UPSs. All UPSs react in the same manner as if the action item was active on
that UPS.
Wiring EPO switch in parallel
It is recommended to use separate EPO circuit for each parallel unit.
4.5.3

Installing Bypass Control Wiring

1. During the installation, follow all the safety instructions given in the 93PR User's and Installation Guide.
2. A 12-pin terminal block for external parallel control signals is accessible on the right side of the
communication interface, on the top section of the UPS. (See Figure 4-8: Communication interfaces.)
3. The Phoenix Contact
1. External parallel connector
Figure 4-8: Communication Interfaces
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1
25-75 kW
User's and Installation Guide