SNK ARR-F5-S1 Flame Detector Relay for Pilot Burners

Name: SNK ARR-F5-S1 Flame Detector Relay for Pilot Burners
Brand: SNK (Shin-Nippon Keisetsu)

Overview

The SNK ARR-F5-S1 flame relay is a compact flame detector relay for pilot burners equipped with a flame rod. It detects the flame between the pilot burner body and the flame rod, amplifies the signal and switches a contact output to indicate the presence of combustion, functioning as a safety device for burner management. This SNK ARR-F5-S1 flame relay is supplied as a genuine spare for SNK burner systems.

Despite its small size, the ARR-F5-S1 is engineered with immunity to ignition voltage interference on the input line and strong noise resistance, giving reliable flame detection in the electrically noisy environment of a burner train.

Engineering & Design

The SNK ARR-F5-S1 flame relay operates from a 100/200 V AC supply (+/-10 %, 50/60 Hz) with a power consumption of approximately 5 VA. The input signal comes from the flame rod rectified current of 2 μA or more. Detection and extinction response time is approximately 0.3 to 1 second, and an LED lights when flame is detected, together with an ignition indicator lamp.

For a reliable installation the flame rod is connected with high-frequency cable such as RG11/C or 7C2V equivalent, run in its own dedicated conduit and kept away from ignition and power cabling, because the flame signal is a small rectified current and is sensitive to interference. The SNK ARR-F5-S1 flame relay detects the flame when the rectified current from the flame rod reaches 2 μA or more, and the LED gives a clear local indication of the flame state. The ARR-F5-S1 is a direct spare for SNK panels and can also be used to upgrade older flame supervision circuits that use the same flame-rod principle.

The output relay contacts are rated 250 V AC, 1 A. When flame is detected, the contact between terminals 3 and 5 closes. The relay is built in an ABS resin case and mounts on an 8-pin plug-in sub-base: the standard OMRON 8PFA sub-base fits a 35 mm wide DIN rail. Ambient operating temperature is -20 to +55 °C (no condensation). The flame rod must be connected with high-frequency cable (RG11/C or 7C2V equivalent) in a dedicated conduit.

Key Features

SNK ARR-F5-S1 flame relay for flame-rod pilot burners
Detects flame between burner body and flame rod, contact output
100/200 V AC supply, approx. 5 VA consumption
Response time approx. 0.3-1 s; LED flame indication
Output contacts 250 V AC, 1 A; terminals 3-5 close on flame
8-pin plug-in sub-base (OMRON 8PFA), 35 mm DIN rail, ABS case

Applications

Pilot burner flame supervision in boilers and heaters
Burner management safety circuits
Flame detection on process furnaces and incinerators
Replacement of failed flame relays in SNK burner systems

Specifications

Manufacturer	Shin-Nippon Keisetsu Co., Ltd.
Type	ARR-F5-S1 flame detector relay
Supply	100/200 V AC +/-10 %, 50/60 Hz
Power consumption	Approx. 5 VA
Input	Flame rod rectified current, 2 μA or more
Output contacts	250 V AC, 1 A (flame: terminals 3-5 ON)
Response time	Detection/extinction approx. 0.3-1 s
Ambient temperature	-20 to +55 °C (no condensation)
Mounting	8-pin plug-in, OMRON 8PFA sub-base, 35 mm DIN rail
Case material	ABS resin; LED indication

Compatibility

The SNK ARR-F5-S1 flame relay is the original relay for flame-rod equipped pilot burners and the direct spare for SNK burner management panels. The standard OMRON 8PFA sub-base and 35 mm DIN rail mounting simplify retrofit in existing cabinets.

Ordering Information

Order the SNK ARR-F5-S1 flame detector relay as a direct replacement for the original relay in your burner system. Confirm the supply voltage setting (100 V or 200 V AC) of your installation before ordering.

Why Seven Star LLC

Seven Star LLC supplies burner and safety components to plants across Oman and

Our engineers help you verify the exact model and revision before ordering, avoiding costly mismatches.

Request a Quote for SNK ARR-F5-S1 Flame Detector Relay for Pilot Burners

For the SNK ARR-F5-S1 flame relay or any related control and instrumentation requirement, contact the Seven Star LLC team. Submit a formal inquiry through our RFQ page with your configuration and application details, and our specialists will respond with a detailed commercial proposal and the official SNK documentation.

Confirming the Right Replacement

Before ordering, read the full type designation on the side label of the installed relay and confirm it reads ARR-F5-S1. Note the supply voltage setting used in your panel (100 V or 200 V AC), the sub-base type, and the burner or panel drawing reference. If the relay is part of a packaged burner, the burner manufacturer’s parts list usually confirms the relay type as well. Where an older relay is being replaced with a different model, check that the flame-rod principle, output contact arrangement and response time are compatible with the burner controller.

Checking the Flame Signal During Commissioning

A flame-rod system relies on a small rectified current, so the quality of the installation decides how reliable the flame detection will be. After installing the relay:

check that the flame rod sits in a stable part of the pilot flame and is not touching the burner body;
confirm the burner body is properly earthed, since the flame current returns through it;
run the pilot and confirm the LED shows a steady flame signal with no flicker;
shut off the pilot fuel and check that the relay drops out within its response time;
confirm the burner controller locks out correctly on flame failure.

Maintenance and Troubleshooting

Nuisance Flame Failures

Check the flame rod for oxide build-up, cracks in the ceramic insulator and loose connections. A dirty or bent rod, or a pilot flame that lifts off the rod, reduces the flame current and may cause intermittent trips. Also check the flame rod cable routing, as coupling from ignition cables is a common source of trouble.

Flame Signal With No Flame

This is a safety fault and must be investigated before the burner is returned to service. Look for a short between the rod and the burner body, moisture or carbon tracking on the insulator, or damaged cable insulation.

Include the flame failure response in your periodic burner safety checks and record the results.

Applications in Oman and the GCC

SNK relays are found on pilot burners of boilers, heaters, furnaces and incinerators, often in packaged systems supplied with Japanese burner equipment in refineries, utilities and industrial plants across the region.

Sourcing Through Seven Star LLC

Send Seven Star LLC the relay label details and panel voltage, and we will confirm the match and provide a quotation and lead time.

Related Products

SNK ARR-F5-S1 flame detector relay

The ARR-F5-S1 is the only SNK part on our site, in the fire and gas detectors category. We could not confirm its technical data against published manufacturer documents, so we do not state ratings here. The reference for any order is the nameplate of the relay in your panel and the burner vendor's documentation.

Ordering an SNK flame relay: what we need

Send the full type from the nameplate, including the suffix after the last dash, the supply voltage and frequency, and the serial number. Tell us which flame detector or flame rod is connected, and name the burner or package vendor. Photos of the nameplate and of the wiring diagram inside the cover are very useful.