Fan voltage

[Snowy Rivers]

Has anyone here ever measured the voltage going to the room air fan when its running on the low setting ???

I know these run off a triac control, but I am currious of the voltage at the fan.

Any input would be great

Snowy

 

[Harvey Schneider]

Measuring Voltage on the output of a triac is a very iffy thing. Depending on the qualities of the meter you can get drastically different readings. A meter that claims to do true RMS measurements might give you meaningful results, but beware of cheap meters. They will be all over the place.
Now I should ask. What is the real question that makes you want to measure the Voltage in the first place?

 

[Arti]

Has anyone here ever measured the voltage going to the room air fan when its running on the low setting ???

I know these run off a triac control, but I am currious of the voltage at the fan.

Any input would be great

Snowy

I've checked a half dozen convection fans,
Most controls increment 10 Volts at a time.
In other words at number 1 heat setting the voltage to the convection fan would be approx 80 Volts, 2 would be 90 and so on with number 5 being line voltage (120 volts)

 

[tjnamtiw]

Hi Snowy,
I got this from the service manual for a Quad Castile >
Combustion blower >
CHECK FOR POWER AT THE BLUE WIRE ON THE CONNECTOR
A. IF POWER IS PRESENT------REPLACE THE EXHAUST BLOWER
B. IF NO POWER------CHECK THE WIRE HARNESS OR REPLACE THE CONTROL BOX
NOTE: OPEN CIRCUIT VOLTAGE IS MEASURED WITH THE BLOWER DISCONNECTED FROM THE WIRE
HARNESS. CLOSED CIRCUIT VOLTAGE IS MEASURED WITH THE BLOWER HOOKED UP TO THE HARNESS.
ONE LEAD FROM THE VOLTMETER MUST BE CONNECTED TO THE BLUE WIRE ON THE MOTOR
AND THE OTHER LEAD CONNECTED TO THE WHITE WIRE FROM THE POWER SUPPLY.
CLOSED CIRCUIT VOLTAGE WILL BE: 115 V (HIGH) 105 V (MEDIUM) 102 V (LOW)
OPEN CIRCUIT VOLTAGE AT THE BLUE CONNECTOR WILL BE 115 V ON THE HIGH SETTING ONLY

And Convection blower >
CHECK FOR POWER AT THE PURPLE WIRE FROM THE #11 PIN AT THE SNAP DISC
A. IF POWER IS PRESENT ON BOTH SIDES OF THE DISC: CHECK THE WIRE HARNESS OR REPLACE
THE CONVECTION BLOWER
B. IF POWER IS PRESENT ON JUST ONE SIDE: REPLACE THE SNAP DISC
C. IF NO POWER IS PRESENT: CHECK THE FUSES & WIRE HARNESS OR REPLACE CONTROL BOX
OPEN CIRCUIT VOLTAGE TO ONE SIDE OF SNAP DISC WILL BE 115 V FOR THE HIGH SETTING ONLY
CLOSED CIRCUIT VOLTAGE WILL BE: 115 V (HIGH) 94 V (MEDIUM) 84 V (LOW)

Hope that helps.

 

[Stovensen]

Hi Snowy,

On pages 7 and 8 in the service manual for the Advantage II T we actually find some charts with the voltages for the blower motors and the auger intervals. Both generations of control boards are dealt with.
Control panel with rotary knobs:


Newer control panel with touch pads:

If you don't have the service manual I've attached it below this post. There are many useful informations in this manual.
Like Harvey Schneider states... the quality of the meter will influence the reading. In the service manual they are using a high quality Fluke 21 Multimeter. The best way to diagnose the triac output, however, is to use an oscilloscope. A couple of years ago my Quest Plus had a rather annoying whining sound from the convection blower motor. I hooked my handheld scope to the test ports on the panel and made a Youtube clip of it. You can clearly hear the whining on setting 3. Also, we can see that the triac output voltage is ok ( = symmetrical ).

Note: The 10V/Div range must be multiplied by 10, since I'm using a 10:1 voltage divider probe in order to protect the scope input from overload. It can max. handle a 80 V peak-peak signal.
The trigger has some difficulty handling the chopped triac signal, and so does the frequency counter... it interprets the signal to be 100 Hz. The line voltage here is 230 V, 50 Hz, but still a proper diagnose is possible.

To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

Accept third party cookies

[/quote]

Later I found out that these annoying harmonics from the triac-signal are perfectly normal, and that the stove has a built in workaround ( factorymade ). You see, the whining can be tweeked to silence by a trimpot on the rear side of the control board. Now, after a little tweeking, my room blower runs perfectly silent.
Good luck and keep us posted.

 

[Snowy Rivers]

Sweeeeeeeeet

Thanks for the info troops.

My reason for asking, is that I found a new relay that will work on the Whitfield Prodigy 2
The specs call out that the control voltage rating is from 90- 280 VAC

The minimum voltage where the relay will drop out is 10 VAC

This relay switches on the booster exhaust fan in the exhaust housing when the stoves main switch is flipped on.
Once the snap switch in the housing reaches 140F the AC power is routed directly to the fan and will keep the fan energized until the fire is out, even if the switch is turned off.

The original relay is no longer offered, but the one I found is from the same company "SSAC" and seems identical.

My worry was if the control voltage would be enough to activate the relay, as the power originates from the control feed to the room air fan, which is fed off the triac and controlled by the feed setting.

The feed setting is a 5 position knob, with 1 being low feed and low fan speed.

The fan has a hall effect sensor in it, and so IIRC the fan gets full power to start and then adjusts to whatever the speed setting is after the fan spools up.

The exhaust fan runs at full line voltage/full speed.

I have considered a one shot timer, but wanted to keep the thing near stock, as it's a friends stove, and they dont wan't to do a rewire.

My personal Prodigy was rewired with a one shot timer that turns the booster on when the start button is pressed.

My rewire runs the AC feed for the auger,the booster and such through the low side snap switch once the stove reaches temp.

The original setup does not stop the auger from feeding if the fire happened to go out, and if this happens with my control, it shuts off the power.

The room air fan gets power directly off the main switch through it's own separate triac control.
I can "tweek" the room air fan, which, on the Prodigy has a shunt tube off the plenum that adds air to the burnpot.

The factory settings are just off a tad from what we needed to burn the shells, so adding a tad more fan speed after the fire is established for about an hour keeps the pot cleaner.

I also changed the High limit snaps to a manual reset type, that once tripped, require a button to be pressed.
I did not want the power coming back on if the beast had an over temp. These need to be looked at carefully.

The entire L1 line feeds through the high limit snaps, thus killing all power to the stove should an over temp occur.

The low limit originally controlled only the booster fan, and then was only there to keep the fan running during shut down.

I always kill the power to the auger and let the stove run until cool with all the blowers running.

This keeps draft air as well as convection air flowing through the stove and allows a gradual cool down as the fire burns out.

Having independent control of the auger and the blower is a real good thing.

I see why the factory did what they did, and that was to keep operation as idiot proof as possible.

Sadly, this approach takes away much needed control.

Having the low temp switch control the auger/fuel feed, as well as the booster/draft fan was a good upgrade, as was setting the high limits in the main.

I also added a relay that opens and must be reset in the even of a power outage, to prevent a restart.

This will prevent a smokey mess should the power be off long enough to allow minimal coals in the fire pot.

Just some thoughts

Snowy