American Power Conversion SYMSTRF3I Electrical Requirements, EPO Switch Wiring Required

Electrical Requirements

SymmetraTM			Voltage	Current	Overcurrent	Minimum
		Wiring			Protection
Component			(VAC)	Full Load		Wire Size
					(External)
		Input		26A/Phase when
				online, 50A on
		with Bypass			60Amp 3-Pole	#8 AWG (10mm2)
				L1 and L2 in
		Transformer	380V, 400V,
				bypass
			or 415V
	SYMSTRF3I	Input		26A/Phase when
International		without Bypass		online, 80A on	100Amp 3-Pole	#3 AWG (25mm2)
		Transformer		L1 in bypass
3:1 Model
	Output	220V, 230V,	80A	100Amp 1-Pole	#3 AWG (25mm2)
						or 240V
	Bypass	Input				#8 AWG (10mm2)*
	Balancing		Controlled by system frame.
		Output				#3 AWG (25mm2)*
	Transformer

* Install the bypass balancing transformer no further than 50' (15 m) from the SymmetraTM. If a greater distance is required, factor in voltage drop when selecting wire gauge.

EPO Switch Wiring (Required)

The SymmetraTM Power Array is to be connected to either a dry contact or 24Vdc Emergency Power Off (EPO) switch. The terminal connections for the EPO switch are physically isolated from the primary circuitry of the Power Array system.

EPO Specifications

The EPO circuit is considered a Class 2 and SELV circuit.

SELV is an acronym for “Safety Extra Low Voltage.” SELV is a common term in Europe and IEC standards. A SELV circuit is isolated from primary circuitry through an isolating transformer and designed so that under normal conditions, the voltage is limited to 42.4 Vpeak or 60 Vdc.

A Class 2 Circuit is a common term in North America and in UL and CSA standards. It is defined in the Canadian Electrical Code (C22.1, Section 16) and in the National Electrical Code (NFPA 70, Article 725).

SELV and Class 2 circuits must be isolated from all primary circuitry. Do not connect any circuit to the EPO terminal block unless it can be confirmed that the circuit is SELV or Class 2. If there is a question, use a contact closure switch. Use one of the following cable types to connect the SymmetraTM to the EPO switch:

CL2 - Class 2 cable for general purpose use.

CL2P - Plenum cable for use in ducts, plenums, and other space used for environmental air. CL2R - Riser cable for use in a vertical run in a shaft or from floor to floor.

CL2X - Limited Use cable for use in dwellings and for use in raceway.

For installation in Canada, the cable should be CSA Certified, type ELC (Extra-Low-Voltage Control Cable).

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