Xantrex Technology STXR1500, STXR2500 AC circuit breaker requirements, Planning DC Connections

Installation Planning

AC circuit breaker requirements

The main service panel must dedicate a 15 amp minimum, double pole breaker (120/240 volts AC) to operate the Sun Tie XR.

Planning DC Connections

	DC connections include all the wires and connectors between your PV
	array and the Sun Tie XR’s combiner board. Figure 2-1and Figure 2-2
	show the combiner board and connection points. Figure 2-14and Figure
	2-15show simplified diagrams of the entire installation.
Wire Sizes	The DC connections are made on the combiner board inside the
	Sun Tie XR. The combiner board accepts wire sizes from #6–14 AWG.
	Refer to Table 2-2for minimum recommended wire sizes.
Exceptions	The values in Table 2-2are the minimum recommended wire sizes.
	Installing a large number of wires in conduit or enclosed locations may
	require larger wire sizes. Consult your local or national electrical code for
	more information.
NEC Restrictions	The National Electrical Code (NEC) places restrictions on minimum DC
	wire bending radius. A #6 AWG wire is the largest that may be used on
	the Sun Tie XR when connecting to the individual fused circuits of the
	combiner board.
Table 2-2 Recommended minimum DC wire sizes
		Minimum wire size for specified distance
DC amps (Imp)
	NEC amps	0–25 ft	25–50 ft	50–100 ft
(from PV array)	(amps x 156%)	one way	one way	one way
1.0	1.6	14 AWG	14 AWG	14 AWG
3.0	4.7	14 AWG	12 AWG	10 AWG
5.0	7.8	12 AWG	10 AWG	6 AWG
7.0	10.9	12 AWG	8 AWG	6 AWG
9.0	14.0	10 AWG	8 AWG	Not Recommended
11.0	17.2	10 AWG	6 AWG	Not Recommended

Note: For an installation requiring a two-wire run (positive and negative), the PV array wires can bypass the individual fused combiner board terminals and connect directly to the input terminals (through an externally mounted DC fused combiner box) by using the positive and negative bypass terminals on the combiner board. Refer to Figure 2-2and Table 2-2for connection and wire sizes.

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