flame scanners

[RUE]

I am having problems with a flame scanner shutter fault which is always showing and high burner unavailability due to dirty scanner. what things should l look at?

 

[danw]

I thought that all commercial UV shutter self-check flame detectors were NEMA 4, so that the shutter mechanism is enclosed and isolated from the external environment.

The seal around a quartz window should seal the shutter mechanics from the gases and dirt in the sight tube. Is the quartz window sealed and in good shape?

If your assembly is not tightly sealed and gasketed, then purge some instrument air into the enclosure to keep a very slight positive pressure inside, with respect to the outside.

The shutter requires a high voltage to run. You can look up whatever that value is and check to see if the controller is supplying sufficient voltage.

 

[RUE]

Thanx will check the current ystem for these things.

 

[rootboy]

The tube that it looks through could be crudded up. It happens to us occasionally. The shutter fault should be a different fault entirely.

What make/model of controller are you using?

 

[RUE]

Flame scanner

I Checked the status of the purge air to the scanners and it seems not much attention is given to the fan filter itself and some of the scanners were not even connected. What l am still trying to fing out is the quartz window. l am not sure if our system has it or not. we are using smart scan flame scanners

also the cables from the scanners are dangling and exposed to heat for a length of around 50cm from the scanner. does this not affect the signal?

 

[rootboy]

I Checked the status of the purge air to the scanners and it seems not much attention is given to the fan filter itself and some of the scanners were not even connected. What l am still trying to fing out is the quartz window. l am not sure if our system has it or not. we are using smart scan flame scanners

You'll want to keep them clean. But doesn't your scanner have a signal strength monitor? Is this the 121 model? Do you have one of their UV sources to test the head with?

also the cables from the scanners are dangling and exposed to heat for a length of around 50cm from the scanner. does this not affect the signal?

No, (not if it was a Honeywell anyways) ours are draped over all sorts of toasty things and we haven't seen a failure yet. Hardly an excuse for leaving it this way, but we have other things to fix I guess.