Parallel Operation; Overview; Conditions For Parallel Operation - Magnum Energy MS-PAE Series Owner's Manual

5.0 Parallel Operation

This section provides information about operating the MS-PAE Series inverters in parallel.
Info: The ME-RTR Owner's Manual provides more detailed installation information on
Parallel stacking,
WARNING: The information is this section is meant to supplement the information in
previous sections. To prevent personal injury or equipment damage, you must care-
fully read and follow all instructions and warnings in this Operator's Manual.

5.1 Overview

A single MS-PAE inverter produces 120/240VAC at its rated power (i.e. MS4024PAE provides 4000
watts of inverter power). Parallel stacking synchronizes multiple inverters to work together as a
single inverter/charger system to increase the inverter continuous and surge capacity, increase
the charging capability to the battery bank and increase the AC pass-through capacity.
The ME-RTR router allows the MS-PAE Series inverters to operate in phase by having one of the
inverters operate as the Master and the others as Slaves, which are controlled by the master. When
fi rst turned on, all the stacked inverters are powered and begin to monitor the power required by the
AC load. If the power requirement by the AC load decreases, the slave inverters power down into
Power Standby mode until needed. The Power Standby feature allows the inverters to shut down
to reduce power consumption and quickly begins inverting when the loads demand more power.
Because the paralleled inverters operate as a single unit, the total battery charging capability and
AC pass-through capacity are also increased. This helps with the fuel consumption effi ciency and
available current to transfer to loads when using large generators. When the generator (or utility
power) is connected to the parallel system, the Master inverter fi rst synchronizes, then connects.
Since the Slave inverter(s) follow the Master inverter, they are prevented from connecting until
the Master inverter has synchronized and connected. After the full system has connected, battery
charging begins. This allows a smooth transition from inverter mode to charger mode since the slave
inverters are already synchronized when they transfer the loads and start battery charging.
5.2 Conditions for Parallel System
When connecting units in parallel, the following requirements must be met:
1. Only the MS-PAE Series inverters are capable of being stacked in parallel and models must be
identical for parallel stacking.
2. A maximum of four identical MS-PAE inverters can be connected in parallel.
3. The ME-RTR router must be connected to communicate and synchronize with other MS-PAE
inverters for parallel operation.
4. The Router Sync Cable from Magnum (PN: A80-8306) must be used to connect directly from
the ME-RTR to each inverter. This cable is the only one that meets the parallel system size, data
and insulation requirements and obtain NEC/CEC site approval.
5. The inverters must be connected to the same battery bank.
6. The DC connection cables from the battery to the inverter must be of equal length and size.
7. The inverter's negative terminals of the inverters must be connected together either at the
inverters or at a location close to the inverters (within 18 inches / 0.5 meters).
8. The AC input cables to each inverter as well as the AC output cables from each inverter must
be of equal length and size (length to AC input may be different from length to AC output).
9. Place the MS-PAE inverters close to each other, but allow at least 3" for ventilation purposes
under, above and in front of the inverter.
10. The AC input to every inverter must be from the same AC source and the two 120VAC legs
from that AC source into each inverter input must be 180° out-of-phase from each other.
11. Each inverter must have appropriate AC and DC overcurrent protection.
Info: The MP Series enclosures meet the requirements needed to parallel stack the MS-
PAE inverters and are UL listed and CSA certifi ed for a code compliant installation.
© 2009 Magnum Energy Inc.
Parallel Operation
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