Overshoot

Overshoot

PostBy: av8r On: Sat Feb 08, 2014 1:29 pm

I've been noticing that we're getting a lot of overshoot this year on our LL Hearth with CoalTrol (latest firmware)

This AM I set the CT for 71 and let it do its thing. It's 3 hours later...the CT reads 75 degrees, 79% feed rate (not dropping) and the stove is still cranking full burn, convection fan running at full speed and has been for the last 60 minutes (CT has shown 74-75 for the entire time)

Why isn't the CT dropping the feed or fan rate?
av8r
 
Hot Air Coal Stoker Furnace: Leisure Line Hearth with twin turbos (sounds like it)
Stove/Furnace Make: Leisure Line
Stove/Furnace Model: Hearth model with twin turbos

Re: Overshoot

PostBy: cArNaGe On: Sat Feb 08, 2014 1:33 pm

operator error?
cArNaGe
 

Re: Overshoot

PostBy: av8r On: Sat Feb 08, 2014 1:33 pm

cArNaGe wrote:operator error?


Occam's Razor may apply.
av8r
 
Hot Air Coal Stoker Furnace: Leisure Line Hearth with twin turbos (sounds like it)
Stove/Furnace Make: Leisure Line
Stove/Furnace Model: Hearth model with twin turbos

Re: Overshoot

PostBy: WNY On: Sat Feb 08, 2014 2:52 pm

what was the original setpoint? If you go more than a degree or two, it will keep feeding and increasing the feed rate until the temp is satisfied.

I found that if I just raise it 1 or 2 degrees, and I change the blower FSA to FSM to 40 or 50% a bit higher than the feed rate to move more heat around so it satisfies the thermostat faster. It usually takes an hour or more to come up to temperature if I want to raise it 1 or 2 degrees.

Also, do you have your HLF (Heat loss factor any different then then factory at 0 or 1) ? By raises that, it will increase the feed rate faster, but also more overshoot. I';ve learned that.

Quick Heat, I go into the menu (hold for like 15-20 secs) until the FEED 10 comes up, then hit an arrow, it will feed for 10 mins and then go back to the normal settings. This get it going faster, then I bump the fans up as above to get it to heat faster, then put them back on automatic (FSA). Just a thought.
WNY
 
Hot Air Coal Stoker Stove: Keystoker 90K, Leisure Line Hyfire I
Coal Size/Type: Rice
Stove/Furnace Make: Keystoker, LL & CoalTrol
Stove/Furnace Model: 90K, Hyfire I, VF3000 Soon

Re: Overshoot

PostBy: av8r On: Sat Feb 08, 2014 5:10 pm

Original set point was 67.

When I want quicker warmup I hand stoke it to fill the grate and kick the convection fan up to 50 something, like you. Brings the stove body up to 500 or so in under 10 minutes. I may give it another stoke by hand as I'm walking around just to keep the grate full.

I've not changed anything other than the minimum feed rate and only changed that +2 from default.

If the feedrate was slowing down I'd not worry so much about it, but it continues to crank along. If I drop it to 70 that seems to be some magic number that gets some reaction fairly quickly.

WNY wrote:what was the original setpoint? If you go more than a degree or two, it will keep feeding and increasing the feed rate until the temp is satisfied.

I found that if I just raise it 1 or 2 degrees, and I change the blower FSA to FSM to 40 or 50% a bit higher than the feed rate to move more heat around so it satisfies the thermostat faster. It usually takes an hour or more to come up to temperature if I want to raise it 1 or 2 degrees.

Also, do you have your HLF (Heat loss factor any different then then factory at 0 or 1) ? By raises that, it will increase the feed rate faster, but also more overshoot. I';ve learned that.

Quick Heat, I go into the menu (hold for like 15-20 secs) until the FEED 10 comes up, then hit an arrow, it will feed for 10 mins and then go back to the normal settings. This get it going faster, then I bump the fans up as above to get it to heat faster, then put them back on automatic (FSA). Just a thought.
av8r
 
Hot Air Coal Stoker Furnace: Leisure Line Hearth with twin turbos (sounds like it)
Stove/Furnace Make: Leisure Line
Stove/Furnace Model: Hearth model with twin turbos

Re: Overshoot

PostBy: WNY On: Sat Feb 08, 2014 5:37 pm

I Think does take too long to come back down if it overshoots. I usually just leave me at a set temperature on HOLD.

The Sun really plays havoc on it, it heats up the room and then the temp is satisfied, FR = 0 then the sun goes down and I loose a few degrees and it takes a bit for it to catch up and maintain. And usually overshoots a couple degrees.

It happens.

I keep mine around 65, it maintains a good temp at about 30-50% feed rate depending on the outside temps, it was -4 last night and it was up to 77% feed but maintaining.
WNY
 
Hot Air Coal Stoker Stove: Keystoker 90K, Leisure Line Hyfire I
Coal Size/Type: Rice
Stove/Furnace Make: Keystoker, LL & CoalTrol
Stove/Furnace Model: 90K, Hyfire I, VF3000 Soon