ML-ACR Automatic Charging Relay - 24V DC 500A
7621
Features
500 Amp magnetic latching (bi-stable) relay automatically combines batteries during charging and isolates batteries when discharging and when starting engine
- Includes ML-Series Remote Control Contura Switch PN 2146
- Automatically manages the charging of two large battery banks
- Allows paralleling of battery banks for emergency starting
- 500 Ampere continuous rating to support high-output alternators
- Magnetic Latch (ML)—ACR draws very low current (<40mA to monitor terminal voltage) in the "ON" or "OFF" states, and draws moderate current for very short time when changing state
- Dual sensing—senses charge on both battery banks
- Start Isolation (SI)—can be configured for temporary isolation of House loads from Engine circuit during engine cranking to protect sensitive electronics
- Engine Isolation (EI)—can be configured for isolation of two engines while both are running to protect engine electronics and maximize alternator output
- Senses charging on two battery banks
- LED output to remotely indicate when batteries are combined, isolated, in voltage lockout, or in Start or Engine isolation
- 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
- Label recesses for circuit identification
Documents
InstallationReferenceArticles 
The Benefit of Serrated Flange Nuts ML-Series Heavy Duty ACR Supports High Amp Charging and Emergency Cross Connect Automatic Charging Relay (ACR) ExplainedVideosMarketing MaterialsProduct Certificates
Wiring Diagram
ML-ACR Troubleshooting Guide
Dimension DrawingArticles The Benefit of Serrated Flange Nuts ML-Series Heavy Duty ACR Supports High Amp Charging and Emergency Cross Connect Automatic Charging Relay (ACR) ExplainedVideosMarketing MaterialsProduct Certificates
The Benefit of Serrated Flange Nuts ML-Series Heavy Duty ACR Supports High Amp Charging and Emergency Cross Connect Automatic Charging Relay (ACR) ExplainedMarketing MaterialsProduct Certificates
Specifications
Control Circuit Connection  | Tinned Wire |
| Nominal Voltage | 24V DC |
| Manual Control | No |
| Engine Isolation | Yes |
| Mounting | #10 |
| Start Assist | Yes |
| Start Isolation | Yes |
| Amperage Operating Current | 13mA |
| Amperage Operating Current when changing state | <7.0A |
| Terminal Stud Torque | 140 in-lb (15.82 Nm) |
| Continuous Rating | 500A |
| Intermittent Rating | 700A (5 min) |
| Cranking Rating 30 sec | 1450A DC |
| Minimum Operating Temperature | -10° C |
| Maximum Operating Temperature | 60° C |
| Cable Size to Meet Ratings | 4/0 AWG x 2 |
| Live Current Switching | 300A @ 12V DC |
| Stud Material | Tinned Copper |
| Switching Cycles | 100000 |
| Terminal Ring Diameter Clearance | 1.12in (28.45 mm) |
| Terminal Stud Length | 1.50in (38.1 mm) |
| Terminal Stud Size | 3/8" - 16 (M10) |
| Wire Size | 20 AWG |
| Relay Contact Position | SPEC_HEADER |
| Combine 30 sec | 27.0V |
| Combine 90 sec | 26.0V |
| Open 10 sec | 24.7V |
| Open 30 sec | 25.5V |
| Open High | 32.4V |
| Weight | 2.08lb (0.94 kg) |
Included
| Qty | PN | Product |
| 1 | 2146 | SPDT Remote Control Contura Switch - ON-OFF-ON |
Regulatory Specifications
    |
Optional Accessories
 | 1147 | Remote Control Panel |
 | 1520 | 360 Panel Blank ML-Contura Switch |
 | 9160 | ML Series Link Bus |
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Frequently Asked Questions
Q: Can I ground to the chassis when installing in a vehicle?
A: Run the negative wire for the ACR directly to the battery negative terminal of one of the batteries. A chassis ground is often insufficient to allow proper operation.
Q: Do I need a ground wire for the ACR?
A: Yes, the ACR is an electronic device and needs the ground wire in order to operate. The instructions show an optional switch in the ground wire however the wire is not optional.
