Monitored conditions
- Low oil pressure
- High engine temperature
- Low coolant level
- Alternator or belt failure
Australian Made Since 1978 Quality Reliability Local Support
Bolec BEM502 – Engine Protection Panel Watchdog Panel
$1,500.00
BEM502 Engine Protection / Watchdog Panel — 12–24VDC
Compact automatic protection for stationary diesel engines used on pumps,
compressors, generators and industrial equipment. The BEM502 monitors critical
engine conditions, shuts the engine down on fault and stores the first shutdown condition.
- Low oil pressure, high temperature and low coolant protection
- Alternator / belt monitoring
- Automatic shutdown with LED fault indication
- First-fault memory
- IP56 enclosure; 12–24VDC operation
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Compatibility note
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Comparing with a Murphy Watchdog panel?
See the compact comparison with the Murphy 09PWP12V09, BEM502IRN and BEM302.
Product resources
BOLEC Engine protection panel
Automatic protection for stationary diesel engines
BEM502
Engine Protection / Watchdog Panel
- Low oil pressure protection
- High engine temperature protection
- Coolant level and alternator monitoring
- Automatic shutdown and first-fault memory
- 12–24VDC
bolec.com.au | sales@bolec.com.au | 0480 312 400
BEM502 engine protection panel
Compact diesel-engine protection with automatic shutdown and fault memory
The BEM502 protects stationary diesel engines used on pumps, compressors, generators and industrial equipment. It monitors critical engine conditions, shuts the engine down on fault and stores the first shutdown condition for diagnosis.
- Automatic shutdown
- LED fault indication
- First-fault memory
- Fuel-solenoid and auxiliary outputs
- IP56 enclosure
A4 product summary — print or save as PDF. Print this page
Protection in one panel
Monitor, shut down and identify the original fault
The BEM502 is designed for unattended or remotely operated stationary engines where a fault could otherwise continue until serious damage occurs.What happens on fault
- Shutdown output stops the engine
- LED identifies the fault condition
- First-fault memory stores the original cause
- Auxiliary output can operate an alarm or relay
Application note:The sensors, shutdown circuit and fuel-solenoid or run-coil arrangement must
match the engine. Installation and commissioning should be completed by a suitably qualified technician.
Murphy Watchdog and Bolec panel comparison
BEM502 vs Murphy 09PWP12V09, BEM502IRN and BEM302
This compact comparison focuses on the features that normally determine which panel is suitable. Wiring, sensors and shutdown logic must still be checked for each application.| Feature | Murphy 09PWP12V09 | Bolec BEM502IRN | Bolec BEM502 | Bolec BEM302 |
|---|---|---|---|---|
| Indicative price (AUD) | Approx. $2,800 | $1,788 | $1,500 | $1,028 |
| Automatic shutdown | Yes | Yes | Yes | Yes |
| First-fault memory | No | Yes | Yes | Yes |
| Programmable run timer | Yes | Yes | No | No |
| Pump-pressure monitoring | No | Yes | No | Optional spare input |
| Coolant sensor support | Optional | Yes | Yes | Optional |
| Best suited to | Industrial engine protection | Irrigation and pump engines | Stationary industrial engines | General-purpose protection |
Indicative prices are shown for comparison and may change. Confirm current pricing, sensor requirements and wiring suitability before ordering.
Choose BEM502 when
You need straightforward engine protection, coolant and alternator monitoring, automatic shutdown and first-fault memory—without a programmable run timer.Choose BEM502IRN when
The application also requires irrigation-focused pump monitoring and a programmable run timer.Is the BEM502 a direct replacement for a Murphy Watchdog panel?
It can be a practical alternative in some stationary-engine protection
applications, but it should not be treated as a drop-in replacement without
checking supply voltage, terminal wiring, sensors, shutdown logic and connected loads.
Product data
Specifications
| Model | BEM502 |
|---|---|
| Application | Stationary industrial diesel engines |
| Supply | 12–24VDC |
| Enclosure rating | IP56 |
| Sensor inputs | 6 preconfigured inputs |
| Outputs | 2 — fuel solenoid / run coil and auxiliary alarm or relay |
| Current rating | 30 A |
| Dimensions | 280 × 190 × 130 mm |
The controlled instruction manual and markings on the supplied panel take precedence.
Product overview
See the BEM502 engine protection panel
Product video
https://bolec.com.au/wp-content/uploads/2025/10/Copy-of-Bolec-Electronics.mp4 Documents and support
Instruction manual and application assistance
View BEM502 Instruction Manual Installation, operation and product information.
Technical support Ask about sensors, shutdown wiring or Murphy Watchdog replacement suitability.
Application guides
Related guides
Read practical application notes and product guides from Bolec Electronics.
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