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SECTION 3
INSTALLATION AND INITIAL TURN-ON
PV-100208 Photovoltaic Inverter
Operation and Maintenance Manual
Copyright 2003, Xantrex Technology Inc.
DOCUMENT: 151700
3-1
ISOLATION TRANSFORMER REQUIREMENTS
The PV-100208 UL1741 certification requires the 100 kVA WYE/WYE isolation transformer be wired
between the inverter AC output and the utility interconnection. This custom 100 kVA isolation trans-
former is included with any PV-100208 that requires UL1741 certification (see Appendix in Section 7
for transformer dimensions and specifications). If UL1741 and NEC690 is not a requirement of your
PV installation, you may use any standard dry-type isolation transformer as long as the inverter side is
rated for a minimum of 100 kVA, 208 VAC continuous duty. Contact Xantrex Technology if you have
any questions.
Inverter Side Isolation Transformer Requirements
The inverter side transformer windings may be configured either DELTA or WYE, and must be rated
for 208 VAC.
If a WYE wound transformer is used to interface with the PV-100208, and the PV
array is grounded, the neutral (X0) must be left floating.
If the neutral is tied to ground, the inverter
will suffer irreparable damage.
Utility Side Isolation Transformer Requirements
The utility side isolation transformer windings may be configured either DELTA or WYE, and must be
rated for the utility voltage at the point of utility inter-connection. Check with the utility of jurisdiction
when selecting an isolation transformer configuration. If a WYE wound transformer is used to interface
with the utility, it is not necessary to connect the neutral (X0) to ground. The PV-100208 is a balanced,
three phase, current sourcing inverter, and only operates with the presence of a stable utility voltage.
Single phase grounded loads which may be present between the transformer and utility, will maintain
their existing ground reference at the utility distribution transformer. Grounding the neutral of a WYE
wound transformer may create an “open delta” condition, depending on the utility configuration.
This
condition may keep the PV-100208 from detecting a loss of phase condition on the utility system,
which may allow potentially lethal voltage to be present on the open phase wiring.
Contact your Xantrex Technology distributor if you have any questions regarding isolation transformer
requirements.
Check with the local utility of jurisdiction when selecting the winding configura-
tion of the isolation transformer. Individual utilities may have unique require-
ments related to isolation transformer wiring. Some winding configurations may
keep the PV-100208 from detecting a loss of phase condition on the utility system
which may allow potentially lethal voltage to be present on the open phase wir-
ings.
WARNING
Xantrex Technology requires installing an isolation transformer between the PV-
100208 inverter and the point of utility interconnection. Failure to do so could
result in catastrophic damage to the PV-100208 as well as the utility distribution
system and will void the product warranty.
WARNING