Heads up & a question on oil burner motors

Alan R. Mercurio_3

Hey Big Ed there sure is!

I’m going to paraphrase what I teach in my burner workshops and NORA Silver Courses for Oilheating Technicians. It’s the procedure that is spelled out in the NORA Oilheat Technician’s Manual and recognized throughout the industry. By the way it's a Great Book for a Great Price. And a must have for oilheating technicians in my humble opinion.

Let’s say the burner will not start and you think it’s the cad cell? The procedure for solving this problem is to #1 make sure the thermostat is calling for heat and that
there is proper line voltage to the cad cell relay. Once you have done this remove one lead from the F-F terminals. If the burner starts that means the cad cell is either seeing external light inside the housing, or the cad cell wires might be pinched it could also mean the assembly itself could be shorted or the cell is defective.

To check the operation of the cad cell relay reset the safety switch disconnect the cad cell leads from the primary control. Connect your leads to an ohmmeter.
While the cad cell leads are disconnected start the burner by placing a jumper across the TT terminals on the primary control. <b>Note: make sure you disconnect the thermostat wires first</b> Now before the control locks out you’ll want to jumper the F-F terminals with a 1,600 ohm resistor. If the control locks out while the terminals are jumped, the control should be replaced.

The 1,600 ohm resistor is used because that is the minimum pull-in value for dependable operation. Now if the burner runs with the F-F terminals jumped the problem is in the
cad cell, its wires, or assembly.

The rest of this is not paraphrased and all the information may not necessarily be found in the NORA OTM However it has proven to be reliable for me.

If the burner did run but was going into a lock out condition again you can jump the FF terminals as described above if it does not lock out the control should be ok now while it’s running you’ll need to use your ohm meter again and confirm the proper ohms reading through the cad cell. I like to see a reading between 300 to 500 ohms mainly trying to keep it under 1000 ohms that’s just my personal preference. That number will be higher with newer equipment but we will save that info for another workshop :)if it’s over 1000 ohms you may want to check the positioning of the cad cell, make sure there are no obstructions causing it not to be able to veiw the flame and most importantly make sure you have proper combustion readings. Not enough air or to much air could cause the burner to lock out.

Remember none of this can really be done without the proper knowledge, tools and experience!

Was I long winded? Sorry it’s the Italian in me. You should see how hard it is to type with my hands going all over the place :)~

Your friend in the industry,<BR>Alan R. Mercurio<BR><BR><a href="http://oiltechtalk.com">www.oiltechtalk.com</a><BR><BR>

Dave Yates (PAH)

Getting burned

Twice this heating season we've been stymied by a series of lock-outs on two oil burners. The first one was a new burner under warranty. We didn't do the original installation and the owner was frustrated by the previous contractor's inability to find the problem. It had not been tested and the burner was off its mark for proper combustion. We felt the issue might well be the flame "lifting" away & tripping the cad cell. Tech service at Beckett agreed & we thought it was the end of the problem. Not to be! After repeated trips that yielded no clues, our supplier said they;ve seen this exact scenario play out on a number of new burners and that a new motor would resolve the issue. Beckett agreed, but not for any labor reimbursement. Naturally the owner doesn't feel he should pay & we'll eat the time. Not fair, but he'll remain a customer.

Next one was an exact repeat, but it's an older burner. This time, we suspected the motor might be the issue - even though we couldn't get it to over-amp or fail during a long series of repeated tests. Until yesterday when it went into a locked-up attempted start, which quickly overheated the motor. The primary control locked out the burner before the motor's overload tripped, which explained why everything worked just fine by the time the owner or we hit the reset.

Just a heads up in case you run across a ghostly series of oil burner lock-outs. Might save you some aggravation and money!

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Alan R. Mercurio_3

Dave, if the second call was an older style burner motor (Split Phase) not (PSC) Then the following web page has some helpful information and tips on burner motors. We have the late John Gates to thank for making this available to us and passing it on to Oil Tech Talk.

Burner Motors and Troubleshooting

Your friend in the industry,
Alan R. Mercurio

www.oiltechtalk.com

John Starcher_4

I have seen.............

.....on many occasions where a motor (burner, blower, condenser fan, or otherwise) will amp out just fine, but later be discovered to be the source of a problem.

Had a client with a condensing unit on the roof of their commercial building several years ago. It was, if I recall correctly, a Lennox unit. We were called for a "no cooling" emergency, and found the condenser tripped out on high pressure safety (manual reset). Cleaned the coil (which was quite dirty, BTW)and fired the unit up. Everything was within spec (refrigerant pressures, amp draws, subcooling, etc), so we assumed the problem was a dirty coil.

The next day, same thing - tripped on reset. Now we're thinking a weak high pressure switch?? Long story short, the condenser fan motor would run fine on startup, and amp draw was normal. Only after running for several hours would the amp draw start to climb, and the motor would stop. High pressure switch would trip, and here we go again.

The only way we found it was to start the unit, go somewhere else for a while, and return after 3-4 hours to recheck all readings. Replaced the motor, and it's been running great since.

Starch

Dave Yates (PAH)

good stuff

Alan,

Thanks for the link & I've printed that out for our shop.

The odd thing here was that we'd called tech service and they didn't mention the problems they're having. It was only after chasing our tail for several calls that the details emerged. First from our supplier & then confirmed by the tech service dept. That was the under-warranty parts call & we never did catch that one acting up. But we took their advice and replaced the motor - no more problems, so I gather that was the issue.

On the second call, we were dealing with an older model that no longer carried any warranties from the manufacturer. We cycled through 30-calls on one visit - some initiated by us and the remainder by simply observing and running tests while the boiler cycled. On our final call - yesterday - the motor did a lock-hum while attempting to re-start (btw - new oil pump, so that was already ruled out)and was far too hot to touch by the time the primary tripped. The overload never tripped on the motor, which would have given us the clue needed had it done so.

Passing along the info in case it might help someone else avoid the out-of-pocket expenses.

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Alan R. Mercurio_3

You're very welcome my friend. Looking forward to seeing you in May if not before.

Your friend in the industry,
Alan R. Mercurio

www.oiltechtalk.com

Big Ed

Relay Test

Alan, any reliable test for checking primary relays ?

Terry_14

Know the page WHAT A HELP

Great advice and link I was going to suggest it myself.

Terry
Plan to hug the Grand kids today

Alan R. Mercurio_3

Thanks Terry.

Your friend in the industry,
Alan R. Mercurio

www.oiltechtalk.com

Weezbo

Hmmmm....

Client ran out of oil,45 below outside,general with tigerloop combo,would not reset ..,no problem, i zipp over no tools in hand to reset and get heat rolling.

wont mojo.

so hmmm... check fire eye (clean), wire around primary...

bring it up to temp , run it two cycles...lash the primary back up.....

cold thick fuel so maybe not got enough ump to go...go thru same process again...

called becket fricked with it another hour on the phone....
got it to stay running...next day off on reset again... went by turned switch off and on starts runs fine....

this morning on way to work i stop by no smoke on stack ,drive to another place come back smoke rolling out the stack keep on going...6 mins later got a call...place is cold been off since 4 a.m. "nah i was there 6 min ago" "well it isnt running"

turn around go back...went off on last night and turned it back on a few mins ago... locked back out again. i flip the power off and on off and running..
we check it with the bacharac everything looks good....

while B.Sing about whereto leave the readout i hear the burner stumble.....
"Did you hear that ?" i ask.

"hear what?"

"it stumbled. must be the motor, might be a the oil solenoid on the clean cut or maybe its the pump,last year there were a bunch of pumps recalled" so i look at it ....nah...Hmmmm....."maybe it is a air bubble that is finding some place to live...."

i think the control is too sensitive

and is causing a lock out or there is a problem with the motor,i didnt hear any indication it was the drive couple thick oil sometimes drags it down real heavy and 'walks it' i am not particularily enamoured with this burner in the first place however i am thinking of using it as a boat anchor and getting the riello for this boiler....which i had rathered if i had my Druthers in the first place.

let me also suggest that i looked at the unit heater fan direction, make up air ,opened and closed the garage doors anything that might somehow effect this rather paticular burner in this location.

ok lets talk draw down causes, Logically. They ran out of oil so maybe its thick oil......possibly it is some condensation and ice shards,yet that alone wouldnt continue ....

maybe it is an electronic malfunction that is over heating on the primary were that the case it might be quick enough to cause a stumble yet not a lockout ..the cad cell catchs the flutter is the part overheats at the connection long enough. only problem with that is Things like to continue doing what they have been doing. and it wasnt locking out previously (before running out of oil)

minor vaccume leak? maybe That might explain it buh then again why would that occur out of no where.? i hate to waste time doing service work anymore and havent used a bucket in years.

i am not a parts replacer.

i did pull the gun and the cone is clean.

i am being as honest as possible. to me this primary is either too sensitive to variations of flame within the chamber with thick fuel oil or it is a motor problem ethier way it is soon to be a boat anchor.

steve_93

That's why I just purchased an Onwatch!!!

Thank's Alan for one heck of a price and great service!!!

I refuse to be a parts changer and many of these problems are intermittent, as we all know, many electrical components can't be tested and not solving the homeowners loss of heat problem can make us look like incompetent monkeys.

Onwatch will find the problem.

Sounds like an advertisment, but it works for us!

Alan R. Mercurio_3

You're very welcome, Steve and thanks again for your business.

Your friend in the industry,
Alan R. Mercurio

www.oiltechtalk.com