Honeywell EC7850A1072 7800 Series Burner Control Relay Module
Honeywell 7800 Series Relay Module
EC7850A1072 Burner Control
2-Second Initiate Timing
Brand Name:
Honeywell
Honeywell 7800 Series Relay Module
,EC7850A1072 Burner Control
,2-Second Initiate Timing
Honeywell EC7850A1072 Relay Module
A 7800 Series microprocessor-based burner control relay module for automatic gas, oil or combination-fuel single-burner applications using full modulation. Its control functions include burner sequencing, flame supervision, operating-status indication and diagnostics.
Manufacturer-listed product: DiscontinuedTechnical Specifications
| Model | EC7850A1072 |
|---|---|
| Product series | 7800 Series |
| Product type | Microprocessor-based integrated burner control relay module |
| Burner application | Single-burner, full-modulation power burner |
| Fuel application | Gas, oil or combination fuel, subject to the approved system configuration |
| Supply voltage | 220–240 Vac (+10% / −15%) |
| Supply frequency | 50/60 Hz (±10%); frequency selection depends on the ordering configuration |
| Initiate period | 2 seconds |
| Pilot stabilization | 3 or 5 seconds, according to the configured sequence |
| Main trial time | 5 seconds |
| Post-purge | 2 seconds |
| Product status | Discontinued on Honeywell's product page |
Additional Technical Data & System Requirements
Electrical and environmental ratings
| Relay module power consumption | 10 W maximum |
|---|---|
| Keyboard Display Module power | 3 W maximum |
| Keyboard Display Module supply | 13 Vdc peak, full-wave rectified (+20% / −15%) |
| Maximum connected load | 2000 VA for the complete assembly |
| Maximum total-load fuse rating | 20 A |
| Operating ambient temperature | −40°C to +60°C |
| Storage temperature | −40°C to +65°C |
| Humidity | 85% RH continuous, non-condensing |
| Vibration rating | 0.5 G environment |
| Relay module weight | 0.730 kg, unpacked |
| Keyboard Display Module weight | 0.113 kg, unpacked |
Sequence timing
| Initiate | 2 seconds |
|---|---|
| Preignition | 3 seconds |
| Pilot stabilization | 3 or 5 seconds |
| Main trial | 5 seconds |
| Main stabilization | 3 or 5 seconds |
| Post-purge | 2 seconds |
| Purge waiting period | Determined by the selected ST7800A purge timer card |
Required system components
The published product data identifies the following components as necessary to complete the system:
| Panel-mount subbase | Q7800A |
|---|---|
| Flame signal amplifier | Compatible plug-in amplifier selected for the flame detector and fuel application |
| Purge timer card | ST7800A series; selectable purge timing from 2 seconds to 30 minutes |
| Keyboard Display Module | Optional; provides sequence information, status display and diagnostic information |
Control and diagnostic functions
The five sequence LEDs indicate Power, Pilot, Flame, Main and Alarm. The five-function Run/Test switch supports sequence testing. With a compatible Keyboard Display Module, available information includes sequence status and time, hold and lockout status, flame signal strength, cycle and operating-hour totals, the six most recent fault records, software revisions and configuration-jumper status.
EC7850A terminal ratings
| Terminal 3 — AL | Alarm output, normally open; 220/230/240 Vac, 1 A; 10 A inrush for 5000 cycles |
|---|---|
| Terminal 4 — L1 | Line supply, 220–240 Vac (+10% / −15%), 50/60 Hz (±10%) |
| Terminal 5 — FAN | Burner/blower motor; 220/230/240 Vac, 4 A at PF 0.5, 20 A inrush |
| Terminal 6 — RT | Limits and burner control; 220/230/240 Vac, 5 A maximum |
| Terminal 7 — LD2 | Airflow switch input; 220/230/240 Vac, 1 mA |
| Terminal 8 — PV1 | Interrupted pilot valve; 220/230/240 Vac, 4 A at PF 0.5, 20 A inrush |
| Terminal 9 — MV | Main fuel valve; 220/230/240 Vac, 4 A at PF 0.5, 20 A inrush |
| Terminal 10 — IGN | Ignition; 220/230/240 Vac, 2 A at PF 0.2 |
| Terminal F(11) | Flame signal; 136–220 Vac, current limited |
| Terminals 12–15 | HI, COM, MOD and LO firing-rate connections; 220/230/240 Vac, 0.5 A at PF 0.5. Terminal 16 control voltage: 230 Vac (+15% / −19%). |
| Terminals 17–20 | Preignition interlock, low-fire switch, high-fire switch and lockout inputs; 220/230/240 Vac, 1 mA each |
| Terminal 21 — PV2 | Intermittent pilot valve; 220/230/240 Vac, 4 A at PF 0.5, 20 A inrush |
| Terminal 22 — SHTR | Shutter drive for a dynamic self-check flame sensor |
Terminal ratings are reference data from Honeywell Product Data 65-0200. Actual wiring, load limits, flame-detection selection and safety checks must follow the complete manual and the approved burner design.
Application & Failure Scenarios
System application
Used in compatible Honeywell 7800 Series control arrangements for automatically fired, full-modulation single-burner equipment.
Replacement and troubleshooting needs
Customers may search for this model when investigating burner lockouts, abnormal startup sequencing or a suspected relay-module fault. These symptoms alone do not establish that the module is defective.
Potential downtime impact
A fault in the burner-control chain can prevent startup or interrupt combustion, stopping the associated heating or industrial process equipment. Diagnosis and replacement should be handled by qualified combustion-control personnel.
Ordering & Configuration Check
Compare the complete model marking, supply rating and installed control arrangement before ordering. The replacement must match the burner application and required control-system configuration.
Installation, wiring, commissioning and safety checks must follow the applicable Honeywell instructions and burner manufacturer's requirements.
AMIKON Supply & After-Sales
AMIKON supports industrial spare-parts sourcing for maintenance and equipment-recovery requirements.
| Pre-shipment Item and order details checked before dispatch; available inspection scope confirmed with the quotation. |
Packaging Protective packaging selected for the item and shipment requirements. |
| DOA / Returns Report suspected arrival faults promptly with order details and supporting evidence. Return authorization is confirmed case by case. |
Warranty Coverage and duration follow the applicable quotation or order confirmation. |
Request a Quote
Provide these details to help us check sourcing options and delivery requirements.
| Part Number EC7850A1072 |
Quantity Required quantity |
| Destination Country / delivery location |
Required Date Requested delivery date |
| Machine/System Model Burner, boiler or equipment model |
|
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Frequently Asked Questions
1. What is the Honeywell EC7850A1072 used for?
It is a 7800 Series relay module for automatic full-modulation burner control, including burner sequencing and flame supervision.
2. What supply voltage does EC7850A1072 require?
The published rating is 220–240 Vac, with a tolerance of +10% / −15%. Confirm the installation requirements against the equipment documentation.
3. What does the 2-second specification mean?
The model's published sequence timing lists both a 2-second Initiate period and a 2-second Post-purge period. They are separate stages of the operating sequence.
4. Is EC7850A1072 still manufactured by Honeywell?
Honeywell's product page identifies the product as discontinued. Contact AMIKON to enquire about sourcing options and confirm the exact item offered.
5. What information should I provide when ordering EC7850A1072?
Provide the full part number, quantity, destination, required date and machine/system model. A photo of the installed unit's label can also help confirm identification.
Product Documentation
For EC7850A1072 pdfenquiries, refer to Honeywell Product Data 65-0200 for the 7800 Series EC7830A and EC7850A relay modules. The document includes electrical ratings, sequence timing, installation and wiring, operating instructions, checkout and troubleshooting.
Official manufacturer document: Honeywell Product Data 65-0200 (PDF).
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