Low High Low Firing question

Yois

I manage a 4 floor 12,500 sq. foot building.  We had a Smith 19A-6 installed in Jan 2009.  The unit ships with a Carlin 702 oil burner.  The Carlin OEM manual says to use a Hago 3.75 60P nozzle, and use a LHL firing setting.  (That nozzle is now out of production, which is part of my question, just wait...)  The installer who set it up said that the High fire setting was "over-firing".  He just used the low fire setting, and set pressure at 140psi.  (Basically as if we had a Carlin 301) I still don't have a CA to check whether he's right, but there weren't any issues at the time, and it didn't take more than 25 minutes to get steam upstairs from a cold start.



At our most recent cleaning, we discovered that a 3.75 in that angle isn't available in any brand.  The tech tried for hours to try various other angles and patterns, but they all burned with quite a bit of smoke and positive draft.  We now have a 3.50 60SS in there, which besides running ineffeciently, it  takes about 50 minutes from a cold start to get steam upstairs.  With the price of oil the way it is, that is killing us.



I wanted to know the following:



I can use a 3.50 GAL 60P nozzle instead of the 3.75, and set up the 2 stage burner the way the boiler was designed to run.  This should save us fuel and make heat up times considerably faster, and if in fact is was "over-firing," the smaller nozzle should solve that.  I'll get a CA to check it.



But...



The installer disabled the Low-High-Low on the burner by disconnecting the switch on the box right by the pump.  (If you know what a 702 looks like you know what I mean).  That's easy to reconnect.  But the only two pressure controls are a L4079B and a PA404A.  It would seem to me that there is no control here that will switch the unit back to low fire, it will just shut it off.  Am I right?

icesailor

Carlin 701:

You need to cal Carlin Combustion Technologies Tech Support:

800-989-2275

I have always had excellent support with them, especially on these burners. And I have never heard of such foolishness as you describe. That burner is sort of bomb proof. It sounds like you need another company to service your burner.

Even call HB Smith. This is quality equipment.

Hago nozzles are now owned by Danfoss. The Hago nozzles are being converted or some tale as such. Someone is not on top of the industry they are working in.

http://hago.danfoss.com/PCMPDF/DKBDPD080A122.pdf

STEVEusaPA

Ice is 1000% right

Just make sure you tell the Carlin rep the pump pressure was changed.

Yois

Calling, but one more question

Thanks guys.  Will call tomorrow.



Regarding the nozzle, I spoke with someone at Danfoss directly, and they confirmed that the 3.75 is out of production until someone is willing to buy 192 of them.  I asked supply houses if they can carry that kind of inventory.  They all said the same thing:  "Just get a 3.50 and turn up the pump."



Regarding potential vaporstat connection, is it just connected in series with the switch on the junction box?

Paul48

Look

Look at "Buy, Sell, Barter". Someone has odd sized nozzles for sale on there.It's worth a try.

Steamhead

According to the manual on Smith's site

low fire on that burner should have the pump pressure set at 100 PSI, high fire 300 PSI. This translates to a high fire rate of 6.5 gallons per hour. But if high fire results in short-cycling, one can drop the high-fire pressure or use a smaller nozzle, and adjust the air input to compensate.



I agree with using a 3.50x60°P nozzle and upping the pump pressure a bit. Hago has been rather obstinate about purchasing quantities since Danfoss bought them, so we might never see a 3.75 again. Both R.E. Michel and Sid Harvey have stopped carrying Hago and Danfoss nozzles for this reason (I'm told).



When using Delavan nozzles to replace Hagos, it is sometimes necessary to go with the next wider spray angle. In this case, a 70° Delavan would replace a 60° Hago.

icesailor

Tidbits:

Steamhead,

Thanks for that informative tidbit. I'll use that somewhere.

I've got an application with 3 WGO-7's and QB-300 (POS's) that require 45 degree nozzles. Does that mean a 60 degree would work better? I boought a box a few years ago and I have run out.