SR501-4 to replace RA832A wiring connections


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Old 11-22-14, 10:12 AM
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SR501-4 to replace RA832A wiring connections

oil-fired hot water, 3 circulators each controlled by a RA832A. I'm replacing a failed controller with a SR501-4 and thus some questions.
The RA832A have 2 "X" terminals, which connect all 3 controllers in parallel to the Aquatstat on the furnace. What are they doing, and how does that relate to installing my TACO?
Terminal 3 on the HOneywell is the output to pump, which I will now feed from terminal 4 on the TACO. Sounds good.
Terminal 4 on the Honeywell is connected in parallel with the other controllers to provide power to the furnace burner (120V). Should I put that wire on the #6 on the TACO?
Seems pretty straightforward to use with a single circulator, but with this parallel wiring from 3 of them I want to make sure I don't have a backfeed issue. Thanks advance for any assistance. Another fun Saturday job.
 
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Old 11-22-14, 04:15 PM
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Terminal 4 on the Taco is the same as terminal 4 on the RA832A.

Terminals 5 & 6 (N/O) on the Taco are the same as X-X on the RA832A.
 
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Old 11-23-14, 09:33 PM
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okay, I see what you're sayin' is also in their manual. But this is why it's not working for me.
The RA832A have 3 sets of switched contacts. On my set-up, when the room TT closes, that energizes the XX contacts, which came from the Aquastat; energizes #3 to power one circ pump; energizes #4 which sends power to the Aquastat and thus the burner. So, with 3 of these RA832A, the power is going individually to 3 diff circ pumps; power to the burner is in parallel; and the XX are in parallel. That's how the RA832A is using 3 sets of contacts. Why? Cuz my aquastat requires closing XX AND getting power from RA832A to operate. Both conditions must be true. I dunno why. Been that way ever since I lived here, at least 10 years. SR501-4 only has 2 sets of switched contacts, thus no way to assure boiler startup. It will start a pump, but the boiler won't start till one of the other (RA832A) zones calls for heat.
So, why isn't this thing set up with either
1) short TT on the Aquastat, so that condition is always met, then the Aquastat gets power to fire from the zone relays
OR
2) provide continuous power to the Aquastat, and use the zone relays to close T-T and fire the burner.
Why do you reckon it's set up so both controls must be true before the burner fires?
Note unrelated but included info it's set as a cold-start boiler, so burner actually only runs within the range set on the aquastat. All of this discussion is just trying to satisfy the external requirements; the aquastat will still look at the boiler temperature to decide whether it needs to fire.
 
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Old 11-24-14, 11:40 AM
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What aquastat are you using?
 
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Old 11-24-14, 12:40 PM
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L8148A

I wonder if mebbe the Aquastat was originally controlled by the t'stat, as it should be, and the first single pump run off the Aquastat relay. Then when they went to 3 zones, they fired each pump from the zone controller, and fired the burner from the zone controller, and just carried the t'stat wiring along out of habit. Dunno.

Seems to me I should run 110 to the Aquastat direct to power the burner, and use the XX controls on each zone to direct the Aquastat to provide burner power.
 
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Old 11-24-14, 01:11 PM
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I have a similar set up except I'm using R845 relays. See figure 26 on page 19 of this manual: http://www.crownboiler.com/manuals/c...n%20Manual.PDF

NOTE: The diagram is mislabled. It is labled as "zone valve" when it is actually for circulators.
 
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Old 02-10-15, 01:38 PM
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I have a similar problem. I just replaced my 55 year old fuel oil boiler with a brand new WEIL-MCLAIN WGO-3, and now I realize I have very poor control(s.) The old system consisted of one RA832A and two RA89A's, which controlled the 3 circulators only. The boiler temp was controlled by high and low limit water temp on the boiler. My installer wants to come back and install a WEIL-MCLAIN circulator control WMCR, which would feed into the HydroLevel hydrostat 3450-plus. Reading the manual, it appears the hydrostat would moderate the water temp according to the thermostats calls for heat, theoretically saving fuel oil. Does this sound like a good idea?
 
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Old 02-10-15, 03:44 PM
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The WMCR looks to be virtually the same as other brands of zone controllers. I looked on Hydrolevel's site & could not find the 3450 plus. What controls the circulators now?
 
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Old 02-10-15, 04:13 PM
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The circulators are controlled by the thermostats, through the RA832A and the two RA89A's. Sorry, I screwed up the model number on the hydrostat. shoulda been 3250-plus. Fuel Smart HydroStat
 
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Old 02-10-15, 04:41 PM
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Your old boiler probably held a lot more water & likely maintained temperature regardless if there was a call for heat or not. With the control system you now have, the burner has no way to know there is a call for heat & fire. The zone panel should cure that problem.
 
 

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