Rio or Epic with flame detector

Greetings. We inherited some flame relays made by Krom Schroeder (model IFW T-N). In a nutshell, these are small 120 volt devices used for the monitoring of gas burners. From the brochure:

Here is what the guts look like (keep in mind this was removed from an existing installation elswhere):

Here is the manual.

Acc. to the manual, the general principle is that as soon as the IFW 15T-N sees a flame, it switches two contacts: a normally closed contact, which is situated between terminals 6 and 7, and a normally open contact, which is situated between terminals 8 and 9. The green lamp indicates that the burner is on.

The manual gives several wiring options (ionization or UV control). We would be installing with ionization, which says this:

Given all of this, does it appear that we could pass the signal from this device into one of our EPICs or Rio’s, so then we can use this information to set off alarms or other logic functions? As far as I can tell, this device is simply looking for continuity of electricity.

Thanks in advance for anyone’s input.

Yes it will work fine

That’s what I thought. Since there are two possible contacts (NC between 6 & 7 and NO between 8 & 9), I was thinking to just send a small voltage amount thru one of these (similar to a reed switch, right)?. Which input on the Rio would be appropriate? Switch input (powered)?

The RIO can “wet” the contact for you - choose Switch input, powered.


Use the terminals 6-7 in the IFW and as Phillip said switch input powered (7) in the RIO. Remember you will get the switch closed when no flame. Did something similar with Fireye E110 and some heat timer’s.

Thanks @jelectron

One more question for the Opto22 guys or anyone who can answer…If we only have an EPIC near these flame sensors, would this be the module to use? To quote

“The GRV-IDCSW-12 module provides 12 channels of contact status input. It supplies power to an external dry contact switch and senses switch closure or opening. The channels can also be configured as DC inputs with a nominal range of 5–30 V.”


In short, what the SNAP, EPIC and RIO switch input/module does is take a small voltage, around 17v DC on one terminal and looks for it coming back on the other terminal.
Thus you can quickly wire a dry contact and pick up the digital state very cleanly.
The really nice thing is that you can do it over many hundreds of feet of wire.

Thank you @Beno

Will report back once I have this little guy set up and running.

BTW, This module is great for many reasons, it saves you time and parts providing the power to contacts when used to check on VFD’s failure output relays, current switches indicating machinery running, IR and UV flame detectors, etc.

1 Like