The Honeywell A4021A1002 is a microprocessor-controlled Valve Proving System (VPS) designed for safety-critical gas-fired burners and large-capacity installations exceeding 1200kW, complying with EN676 standards. It performs automatic, self-checking tests on up to three automatic shut-off valves by measuring pressure differentials between valves during pre-purge, post-purge, or on-demand sequences, ensuring leak-free closure before ignition. Upon detecting a fault, it enters a non-volatile lockout, activates an alarm, and blocks burner startup, enhancing combustion safety when paired with a ZL030001 subbase and pressure switches.
Key features include dynamic relay testing, safe start verification, and clear LED diagnostics for test sequences and faults, with support for remote reset and compatibility with Honeywell 7800 or Satronic controllers. Housed in an IP40 enclosure (including subbase), it offers robust operation across -10°C to +60°C and 0-95% RH, with no field calibration needed for reliable, maintenance-free performance in industrial heating systems.
Technical Specifications
| Parameter | Specification |
|---|---|
| Model | A4021A1002 |
| Type | Valve Proving System (VPS), microprocessor-based |
| Supply Voltage | 220-240 VAC, 50 Hz |
| Power Consumption | Max 4.5 VA |
| Test Time per Valve | 25 seconds |
| Outputs: Valve | 4A, cos φ 0.7 |
| Outputs: Vent Valve | 1A, cos φ 0.7 |
| Outputs: Ignition Controller | 4A, cos φ 0.7 |
| Outputs: Alarm | 2A, cos φ 0.7 (voltage-free) |
| Fusing: External/Internal | 16A slow max / 5A slow max |
| Ambient Temperature | Operating: -10°C to +60°C; Storage: -40°C to +80°C |
| Humidity | 0-95% RH at 40°C (non-condensing) |
| Enclosure | IP40; Weight: 0.65kg (with subbase) |
| Required Accessories | ZL030001 subbase, pressure switches |
| Approvals | EN676 compliant for >1200kW gas systems |
