Inverter/charger: magnum ms series
What it does
The Magnum MS inverter/charger has two jobs. With good shore or generator power on the input it closes an internal transfer relay, passes that AC straight through to the inverter output (Standby) and charges the batteries. Without it, it inverts battery power to 120 VAC.
The front ON/OFF switch does NOT turn the charger or pass-through off. If qualified AC is on the input it is on the output too.
Read the green LED (watch at least 10 seconds)
OFF|Inverter off or faulted|Low battery, high battery, overload, over-temperature or internal fault. See below.
SLOW FLASH (1 per 8 s)|Float charging, Standby|AC input is passing through to the loads. Normal.
MEDIUM FLASH (1 per s), no AC in|Inverting or Searching|Search mode waits for a load over 5 W (default). Small loads like a clock may not wake it.
MEDIUM FLASH, AC in|Absorb charging, Standby|Normal.
SOLID ON|Bulk charging, Standby|Normal.
Shutdown levels (MS2000/MS2012/MS2812)
LOW BATTERY CUT-OUT|10.0 VDC after 1 minute (adjustable 9.0-12.2 with a remote); 8.5 VDC immediate
LOW BATTERY CUT-IN|12.5 VDC (auto restart), or when AC charging starts
HIGH BATTERY CUT-OUT|above 16.8 VDC; restarts at 16.5 VDC
High battery shutdown is usually solar or the alternator over-charging. Turn the other charge source off and let the voltage drop.
Faults
Overload/short: shuts down after a few seconds. Reduce loads (or remove AC output wiring) and turn it back on.
Over-temp: LED off, restarts on its own after cooling. Check ventilation and load.
Internal fault: needs a reset.
Reset
Press and hold the ON/OFF button about 15 seconds until the LED comes on and flashes rapidly, then release. The LED goes off. Press ON/OFF once to turn the inverter on. Removing DC power also resets it. Fault won't clear = service.
Factory defaults
SHORE MAX|30 A
SEARCH WATTS|5 W
LBCO|10 VDC
BATTERY TYPE|Flooded lead acid
BATT AMP HOURS|600 Ah (absorb 120 min)
VAC DROPOUT|80 VAC
TRANSFER RELAY|30 A per leg
Default battery type is FLOODED. A lithium or AGM bank on default settings is being charged wrong. Settings need a remote (ME-RC, ME-ARC, ME-RTR) and are stored in the remote.
Low output or weak surge
Loose or corroded battery cables; wrong cable gauge or length; low batteries; loose AC output terminals.
Every 6 months: battery terminals 10-12 ft-lb, inverter AC terminal block 16 in-lb, batteries within 0.3 V of each other.
MAGNUM|Magnum Energy MS Series Inverter/Charger Owner's Manual (2012): sections 3.4-3.7, 4.3, 4.4 (via myrvworks.com)