Blue Sea ML-ACR

Blue Sea ML-ACR

Information

The Blue Sea Ml-ACR 500 Amp magnetic latching (bi-stable) relay automatically combines batteries during charging and isolates batteries when discharging and when starting engine.

It uses the charging voltage to decide when to connect truck batteries to camper batteries and when to disconnect.

There is an override switch to force disconnect batteries during maintenance. There is also an optional remote function available as an add-on. 

  • Manual override knob provides an added level of safety allowing control with or without power and offering LOCKED OFF capability for servicing
  • LED output to remotely indicate switch state -requires optional LED
  • 3.8″-16 tin-plated copper studs for maximum conductivity and corrosion resistance
  • 7/8″ (22mm) stud length accepts multiple cable terminals
  • Silver alloy contacts provide high reliability for switching live loads
  • Waterproof – rated IP66 from water projected in powerful jets

blue sea ml-acr

 

Problems

None Reported

No problems reported yet

Tips

TROUBLESHOOTING PDF

Blue Sea have produced a flow chart trouble shooting guide for the ACR. Click the button below.

(James Young)

TROUBLESHOOTING with a Multimeter

In most cases, ACR issues can be diagnosed by a few tests with a multi-meter.

mc-acr wiring diagram

mc-acr multimeter test

Step 1: Check all fuses and/or circuit breakers connected to the ACR.” There could be up to (3): (1) on each battery positive wire to the ACR, and (1) on the ACR Ground wire.

Step 2: Unplug the SI (Start Isolation) wire if one is connected.

Step 3: Check battery voltage with charging OFF and batteries at rest”

 

Test 1: Voltage of Battery A at the battery terminals

Voltage reading: _____________

Test 2: Voltage of Battery B at the battery terminals

Voltage reading: _____________

Test 3: Voltage between the ACR ground wire (-) and Terminal A (+) of the ACR.

Voltage reading: _____________

Test 4: Voltage between the ACR ground wire (-) and Terminal B (+) of the ACR

Voltage reading: _____________

 

Step 4: Check battery voltage with a charging source, or engine, ON one battery. Wait 2 min after applying the charging source before taking readings

 

Test 1: Voltage of Battery A at the battery terminals

Voltage reading: _____________

Test 2: Voltage of Battery B at the battery terminals

Voltage reading: _____________

Test 3: Voltage between the ACR ground wire (-) and Terminal A (+) of the ACR. Test 4: Voltage between the ACR ground wire (-) and Terminal B (+) of the ACR Test 5: Voltage between the ACR ground wire (-) and Start Isolation wire (+).

Voltage reading: _____________

 

During charging, battery terminal voltage of at least one battery MUST be above 13.0 VDC, and the second battery must be above 9.5 VDC, for the ACR to Combine. The battery readings should be the same as the ACR terminal to ACR ground voltage readings. The ACR will stay combined until the voltage at the A or B terminals goes below 12.75 VDC. If any voltage is present on the Start Isolation terminal the ACR will “Lock Out” until that voltage is removed. If any battery voltage is below 9.5 VDC the ACR will “Lock Out”, and the battery must be charged before ACR will combine

 

(Markus)