UV scanner testing

[Deleted User]

Is it possible to test whether or not a UV scanner has gone bad? If it is would y'all be willing to share?

Glen

most times -

you can test the sensor. Depending on which flame safeguard relay (fsr) you are using. Some have vdc outputs while others need to be tested for micro amps. And fireye and hw have testing modules where you can simulate full capacity of the fsr including the UV sensor.

[Deleted User]

Who's scanner

are you asking about? What is the number of the flame safeguard relay?

oil-2-4-6-gas

what are the symptoms ---it may be scanner,amplifier,blocked scanner tube etc...

Josh M._2

An un-official but effective test is to hold up a lighter to it while connected to the flame safeguard and see if all of the cells glow. If only part of them glow you have a bad one. This was a trick taught to me by one of Moneywell's (Honeywell) greatest...

[Deleted User]

Thank-you for your responses Gentlemen. THe scanner is a Landis UV working into a Siemens 1.335 LFL flame safeguard. Fuel is either Natural Gas or LPG and the problems are mostly in condensing boilers. Sorry for the incomplete information.

[Deleted User]

Siemens/Landis

Scanners are measured in microamps. The meter (100 MA) must be wired in series w/ the positive scanner lead. A 100 MF capacitor must be wired in parallel w/ the meter. - on the entering side of the meter & capacitor. + on the leaving side. Minimum acceptable signal value is 70.

This is from Riello's RLS I&O Manual. Not one of the Euros better pieces. But, the LFL is cheap.

EBEBRATT-Ed

I agree that that is what the instructions say however I was told by Riello that you do not need to wire the capacitor in parallel. I was reading a flame rod signal and it worked with my analog meter but not with two digital meters I used.

I would like more info on this as well.

Anyone from Siemens out there??

Glen

Fred!

As we are talking Seimens/Landis & Gyr - let me relay my last service call to McBride (VSB 72, LPG). The LFL was indicating failure to recognize flame. Via tx with the building tech we confirmed polarity of the wiring, changed out the LFL for the spare on the shelf, and ensured the "window" of the UV sensor holder was oriented correctly. No success. Off we go - 800km north. Wiring was checked to Weishapt specs, polarity checked etc. Same fsr failure. As part of several service calls to viessmann gear - I have changed out the UV sensor - but not until the hours have racked up on the burner- and this was largely a prophylactic measure. McBride had me scratching my head. I am not sure why - but I popped out the bulb and rotated it 180 deg. voila! c'est magnifique! The Landis bulb is a four prong affair - the bulb holder is only two. So if you have had a building tech fiddle - rotate it 180 first before changing out. As far as a test goes - we need to lobby the Seimens folks to devise a testing platform that will simulate operating conditions. There may be other tests but we were never taught them at the Weishapt certification classes. I have found that if the sensor glows - it's probably bagged. That said - I will now rotate it 180 (the bulb that is) and try again. Ain't it strange that a service item that's 300 bucks a pop yet so simple can give us so much grief???

[Deleted User]

Neat info.

However. Our FSG guys give us connections on their older controls to plug in meters to check the scanner reading. In the new units, a digital readout is incorporated, or carry your own, that not only reads the flame signal, but tells you the operating mode at time of failure, the last 6 (or more) failure modes, & the cycles & hours @ time of failure(s). The stopping of the dial @ point of failure, on the LFL, still leaves you trying to decipher the less than user friendly instructions. This is one time the Euros should be copying from us.

EBEBRATT-Ed

My first LFL. I thought I was watching the cam and dial on an old Fireye 1008.

Ed

Glen

Plug ins -

each Weishapt burner does have a plug in port to check the UV signal. It's very easy to use. The underlying questions to Fred's first post is this - are the UV sensors changed out before full testing is done - how can we ensure that happens in the field before the Viessmann guy is sent long distances, and is there a quick and dirty method of diagnostics via telephone??? Fred is the tech for the Vancouver area - while I handle the eastern part of the province. I change out very few UV sensors while Fred has many returns from the installing contractor - whom in turn expect warranty. Yet when tested in the RMT or VSB boilers in the Langley showroom - work well with strong micro amp signals. So aside from the onboard diagnostic feature of the Weishapt or Riello burners - has anyone devised a method to test just the bulb??? Ohm's etc. We can test cad cells with a static resistance test - is there a similar test for UV sensors?

[Deleted User]

Just talked to

the Maestro @ the largest FSG Distributor in the Mid Atlantic. He relates that the short answer, from MH & Fireye, to testing UV Sensors w/o connecting them to the control is - no.

Glen

yes - that is the prevailing thought

but what if it has yet to be discovered? I'm betting on the brilliant minds that lurk on the Wall - Fred can't be the first to think of this - can he??? (Fred - btw - will not be buying lunch Friday - we addressed the issue by phone)