Harman SF260 Installation Assistance

Harman SF260 Installation Assistance

PostBy: WVUNUT1985 On: Sun Feb 23, 2014 9:12 pm

I have been hanging around reading NEPA Crossroads for quite a while and figured it was time to join. I am in the process of installing a Harman SF 260 indoor boiler and need some advice. Here is the info I have on the system:

single loop supplying a water to air HX in the existing propane furnace plenum.

One tako calculator pump installed.---identical to the install picture in the SF 260 manual.

Plan is to activate the pump via a thermostat running through a Universal Switching Relay w/ Internal Transformer (R8845U1003 Brand: Honeywell)

The system uses a Aquastat A350 for draft control, Y350 Power Module and a S350 stage module to control an overheat dump control.

Here is the question i have---- What is the best way for me to wire the system so the overheat dump zone will turn the circulating pump on in the event of activation. I know in principle, triggering one device from two locations without causing a dual power feed to the motor.

Any help or advice is greatly appreciated.
WVUNUT1985
 
Hand Fed Coal Boiler: Harman SF260
Coal Size/Type: TBD
Other Heating: Propane

Re: Harman SF260 Installation Assistance

PostBy: Rick 386 On: Sun Feb 23, 2014 10:53 pm

I think most guys here wire up a totally separate zone for an emergency dump zone.

Something like a basement or garage zone with big radiation to draw the heat down.




Rick
Rick 386
 
Stoker Coal Boiler: AA 260 heating both sides of twin farmhouse
Hot Air Coal Stoker Stove: LL Hyfire II w/ coaltrol in garage
Coal Size/Type: Pea in AA 260, Rice in LL Hyfire II
Other Heating: Gas fired infared at work

Re: Harman SF260 Installation Assistance

PostBy: nepacoal On: Mon Feb 24, 2014 3:19 pm

I use a Taco ZVC403 to control my pumps. The end switch powers both the circulator loop pump and main house pump. Circuit 1 is tied to a thermostat, circuit 2 is a manual dump switch, and circuit 3 is tied over to the end switch at the sf260. Any of the 3 circuits will turn on the circulator and main house pumps. My dump zone is just going to the normal radiators in my house loops. I do not have a separate dump zone.
nepacoal
 
Hand Fed Coal Boiler: Harman SF-260
Coal Size/Type: nut


Re: Harman SF260 Installation Assistance

PostBy: WVUNUT1985 On: Mon Feb 24, 2014 4:12 pm

Thanks for the information. I will look at the ZVC 403. What you are doing, seems like the same thing I am trying to do. Use the primary zone as the dump zone when needed.
WVUNUT1985
 
Hand Fed Coal Boiler: Harman SF260
Coal Size/Type: TBD
Other Heating: Propane

Re: Harman SF260 Installation Assistance

PostBy: nepacoal On: Mon Feb 24, 2014 8:04 pm

Just have the sf260 in parallel with the oil boiler. I put in 2 main house pumps in series and a single loop pump between the coal boiler and the oil boiler. One main pump and the loop circulator is tied to the sf260 via the zvc403. so it has it's own thermostat along with the automatic and manual dump controls. The oil boiler has it's own thermostat and it's own main house circulator. The house uses cast iron radiators. My sf260 handles all heating duties and the oil will occasionally run for DHW.
nepacoal
 
Hand Fed Coal Boiler: Harman SF-260
Coal Size/Type: nut

Re: Harman SF260 Installation Assistance

PostBy: wilder11354 On: Mon Mar 03, 2014 8:10 pm

the S350 is a switch it has no power running out of it unless you wire power into it.. I ran an extra pair TT wire(s) to my s350 off of my LR zoneR845a relay TT terminals. if zones not running and s350 switches on, will turn on mt LR zone circulator, and primary loop circulator by using LR TT voltage in R845a. If LR zones already on for heat call..., in theroy the boiler should be dumping heat because LR zones on and NOT go into an overfire situation which would activate S350 JC relay . And this has held true. I also have oil boiler, set another S350 on end of JC relays, to comtrol primary circulators for oil boiler/coal boiler so if coals unable to keep up with load and temp drops to setpoint, it shuts of coals primary circulator and switches on oils primary pump and oil heats till coal gets back up to reset temp(differentials) & (offsets) it works excellent.
wilder11354
 
Hand Fed Coal Boiler: Harman SF260
Coal Size/Type: nut or pea, anthracite
Other Heating: crown oil boiler, backup.if needed