Gas Assist For Large Log Burners W/Safety Features

BBQMAN · Posted: Mon Aug 22 16 7:44 pm Post subject:

Had my 2nd failure in 6 years this past weekend. The unit isn't sparking at the burner head. Gas valve manually works if I light the pilot, so I know that, the thermocouple that sees heat and allows the main burner to light, and the blower motor are working properly. Could be one of two things- the Honeywell spark unit itself, or the centrifugal switch on the end of the blower motor that doesn't allow the spark unit to fire until it come up to speed. Stay tuned!
_________________
BBQMAN
"I Turned A Hobby Into A Business".
Providing "IMHO" Since 2005.

BBQMAN · Posted: Thu Aug 25 16 6:48 am Post subject:

Pulled the unit, it was the centrifugal clutch that activates the switch on the end of the blower motor. Cleaned up, works like new.
_________________
BBQMAN
"I Turned A Hobby Into A Business".
Providing "IMHO" Since 2005.

BBQMAN · Posted: Mon Sep 19 16 9:26 pm Post subject:

Pretty simple fix- the centrifuge switch (#5) was sticking. Cleaned it up, checked the switch itself, a little silicone spray, and back into business!

GAS BURNER SEQUENCE OF OPERATION
It is very important to know the sequence of operation when troubleshooting the burner. The below steps describe
the cycle for ignition in the sequence of operation for the burner.
1. The smoker is powered on with the desired cooking temperature set.
2. At a call for heat from the thermostat, 120 volts of power go through the thermostat, the high limit switch,
and on to the burner.
3. The power comes into the burner at the junction box, which is located on top of the blower motor; 120
volts AC go to the primary side of the 24 volt AC step down transformer and to the combustion motor and
the combustion motor comes on.
4. The step down transformer sends 24 volts AC out to the centrifugal switch on the blower motor.
5. When the blower motor is powered up and reaches full speed, the centrifugal switch (located on the end of
the motor) is activated, sending 24 volts through it and on to the ignition control module.
6. When 24 volts reaches the ignition control module, it sends a high voltage spark out to the electrode
(igniter) to light the pilot flame, and at the same time, it sends 24 volts to open the pilot valve on the main
gas valve.
7. After the pilot lights, the electrode (igniter) acts as a flame sensor sending a DC micro amp signal back to
the control module that there is a pilot flame, then the ignition control module sends out 24 volts AC to
open the main valve.
8. The pilot flame lights the flow of gas from the main valve and the burner will fire until the call for heat
from the thermostat has been satisfied, shutting the burner down.
NOTE: The burner is equipped with a ignition module that has a 3-try for ignition sequence.
_________________
BBQMAN
"I Turned A Hobby Into A Business".
Providing "IMHO" Since 2005.

lennyk · Newbie Joined: 17 Sep 2009 Posts: 97

My sc80 fan runs for about three mins before it opens gas and fires the igniter.

Does yours do the same ?

I have been using my gas assist for a few years well after seeing your guide here and could not be happier.

Lennard

BBQMAN · Posted: Fri Sep 23 16 6:42 pm Post subject:

That is normal operation Lenny, and part of the reason for my own issue. If the fan motor doesn't come up to speed the safety switch isn't closed and the igniter/gas doesn't turn on. In my case it was the centrifuge mechanism itself (it didn't throw out to meet the switch contact), not the switch.

So glad you are enjoying the setup, I do a lot of overnight cooks and it's a lifesaver many times over.
_________________
BBQMAN
"I Turned A Hobby Into A Business".
Providing "IMHO" Since 2005.

lennyk · Newbie Joined: 17 Sep 2009 Posts: 97

I often do midnight cooks for lunch next day using
One of those dial timer plugs.
Let it fire itself up at midnight or whenever

BBQMAN · Posted: Sun Apr 01 18 11:48 pm Post subject:

3rd failure in almost 8 years. Blower motor isn’t spinning up, of course the centrifuge switch on the back of the motor isn’t letting gas flow (great fail-safe) so it’s not igniting . Have a pig roast to cook tonight old skool, then will dig into it Tuesday. Happy Easter everyone !
_________________
BBQMAN
"I Turned A Hobby Into A Business".
Providing "IMHO" Since 2005.

jess · Posted: Mon Apr 02 18 5:41 pm Post subject:

Good to see you are still kicking and Q'ing Mike...

BBQMAN · Posted: Mon Apr 02 18 8:52 pm Post subject:

Of course, hope all is well Jess! Opened the restaurant a bit over a year ago. What an adventure.
_________________
BBQMAN
"I Turned A Hobby Into A Business".
Providing "IMHO" Since 2005.

jess · Posted: Tue Apr 03 18 4:57 pm Post subject:

Come on man -"We opened the restaurant" is all you got ? No run down, no pics ? Either someone is posing as BBQMAN or you are some kind of busy...

BBQMAN · Posted: Wed Apr 04 18 1:56 am Post subject:

I’ll see what I can do Jesse, not sure if I remember how to log into my photobucket account lol!
_________________
BBQMAN
"I Turned A Hobby Into A Business".
Providing "IMHO" Since 2005.

BBQMAN · Posted: Wed Apr 04 18 2:11 am Post subject:

Found multiple problems. Years of heat took some abuse on wiring. The connection in the top of the blower motor box on the relay was loose. As in falling off. The rubber bushing between the motor and blower was broken down, allowing the blower fan to rub. Shimmed that out, wrapped up the wiring, reattached the wiring to the relay, bench tested it and put it all back together. Back in bidness, at least for now!
_________________
BBQMAN
"I Turned A Hobby Into A Business".
Providing "IMHO" Since 2005.