Emerson 480V user manual EPO Input-Optional, EPO input contact relays, Indicates Pin

Electrical Connections

2.3.5EPO Input—Optional

The UPS has an Emergency Power Off (EPO) function operated by a button on the control panel or by a remote contact provided by the user. The local EPO button is under a hinged, clear plastic shield.

The X2 slot, shown in Figure 10, is the remote EPO input interface. The EPO has a NO/NC contact point that becomes active when shorting terminals X2: 3 and 4 or open terminal connection

X2: 2 and 1.

If an external Emergency Stop facility is required, it is connected terminals X2: 1 and 2 or X2: 3 and 4 of the auxiliary terminal block (X2). It also is connected to the Normally Open or Normally Closed remote stop switch between these two terminals using shielded cable (see Figure 10 and Table 5). If this function is not used, terminals X2: 3 and 4 must be opened and X2: 1 and 2 must be closed.

Figure 10 EPO wiring

J28

X2

		EPO - NO		NOTE: The black square	indicates Pin 1.
			EPO - NC
Table 5	EPO input contact relays
Position	Name	Description
J28.1	EPO_NC	EPO Activated when opened to J28.2
J28.2	EPO_NC	EPO Activated when opened to J28.1
J28.3	EPO_NO	EPO Activated when shorted to J28.4
J28.4	EPO_NO	EPO Activated when shorted to J28.3

NOTE

The Emergency Stop action within the UPS shuts down the rectifier, inverter and static bypass. It does not internally disconnect the input power supply. To disconnect ALL power to the UPS, open the upstream feeder breaker(s) when the remote EPO is activated.

NOTE

Normally Closed EPO – X2: 1,2, these terminals are supplied factory-linked on the monitor board and must remain installed if using NO contacts.

NOTE

All auxiliary cables of terminal must be double-insulated. Wire should be 20-16AWG stranded for maximum runs between 82 and 197 feet (25-60m), respectively.

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