©
2020 Sensata Technologies
Page 19
Installation
2.5 AC
Wiring
This section provides information on how to make the AC connections to the inverter using the
correct AC wire size and corresponding overcurrent protection.
2.5.1
Pre-AC Wiring Requirements
WARNING
: To reduce the risk of
fi
re, do not connect this inverter to an AC load center
(circuit breaker panel) having multi-wire branch circuits connected.
CAUTION:
Before installing any AC wiring, review the safety information at the
beginning of this manual and the following to ensure a safe and long-lived system:
AC wiring must be copper, approved for the application (i.e., RV wiring), and must be
no less than #8 AWG (8.36 mm²) on the inverter’s input and no less than #6 AWG
(13.3 mm²) on the inverter’s output to allow the full current capacity of this inverter.
DO NOT connect the inverter’s output to an external AC power source. This could cause
severe damage to the inverter and is not covered under warranty.
The wire sizes recommended in this manual are based on the ampacities given in Table
310.17 (in free air) of the NEC, ANSI/NFPA 70, for 75ºC (167ºF) copper wire based on
an ambient temperature of 30ºC (86ºF).
The AC input and output neutrals must be isolated from each other, do not route the AC
input and output neutrals to a common neutral bus.
2.5.2
AC Wire Size and Overcurrent Protection
The AC input and output wiring must be sized per the local electrical safety code requirements
to ensure the wire’s ability to safely handle the inverter’s maximum load current. The AC wiring
must be protected from short circuits and overloads by an overcurrent protection device and have
a means to disconnect the AC circuits. AC overcurrent protection is not included in the inverter
and must be provided as part of the inverter installation. The AC overcurrent protection device
must be a circuit breaker or a fuse/disconnect, and be properly sized and branch circuit rated for
the wire it is protecting and the appliances being powered.
Info:
When wiring the AC input and output circuits, we recommend a full system Inverter
Bypass Switch. This simple item isolates the inverter from the battery, which could save
hours of downtime—if you ever need to perform battery maintenance or service the
inverter—by enabling you to continue to power your AC loads without any re-wiring.
The AC input capacity of the MSH3012RV inverter/charger is limited to 50 amps maximum. This
requires a 50-amp continuous duty rated breaker, which corresponds to a minimum cable size
of #8 AWG (8.36 mm²). If you are using other circuit breakers/wire sizes, refer to appropriate
electrical codes for sizing requirements.
This inverter when connected to an AC source for charging also has an automatically enabled
load support feature. This means the inverter’s AC output current can be greater than the current
supplied to the inverter’s input by the AC source. The output of the inverter can supply 60 amps
AC, this requires a minimum cable size of #6 AWG (13.3 mm²) on the inverter’s output.
CAUTION:
The load support current of this inverter in combination with the inverter’s
input current can supply 60 amps on the inverter’s output. Be aware, if you are installing
this inverter in a coach that is not wired for at least 60 amps on the inverter’s output
circuit, then an appropriately sized over-current protection device (i.e., fuse/circuit-
breaker) must be installed on the inverter output circuit to prevent damage.
CAUTION:
Even though this inverter can provide 60 amps AC on its output in Standby
mode (i.e., AC power is connected to the inverter’s AC input), it can only provide 25
amps AC continuously while inverting in inverter mode (i.e., only using battery power
to power the inverter loads). When inverting, ensure the total current requirement of
the inverter loads are not rated for more than 25 amps AC continuous; or you may
experience inverter overload conditions and/or the inverter loads not operating.
