Steam Boiler, Burner, Pressuretrol old wires.CANT understand what goes to what based on old wiring

LS123

Hello Steam Boiler enthusiasts!

Few days ago I posted here because my burner would not fire up... @Jamie Hall , @Steamhead and and @EBEBRATT-Ed
If anybody has a simple diagram or just steps please let me know...
Based on pics, Ptrol top connector is white wire, bottom is black...
The electrical box that has main power line, another going to the burner, and another going to the Ptroll.... wires are so SO old, I cant figure out what color connect to what, and what line...
Any help would be most appreciated...
Thank you!
( I have Armorlite 100-ft 12/2 Solid Aluminum MC Cable ready to go)

LS123

sorry .. I mean to say "Few days ago I posted here because my burner would not fire up... @Jamie Hall , @Steamhead and @EBEBRATT-Ed gave me valuable feedback... It turned out to be the thermostat... I got a new wires for thermostat and boiler burner, Ptroll and main power line... just cant figure out which wire connect to which, because the wires are so old...

EBEBRATT-Ed

Take some pictures of the boiler and burner so we can see what you have for controls

SteamingatMohawk

The circuit you are working on is a control circuit, not a load circuit. It seems the cable you have is way over capacity and assuming the conductors are solid not stranded it will be a bit harder to run. Is there a specific reason you choose to use it?

LS123

Please find attached.. this used to be a coal steam boiler converted to oil... Not the best... but I like the fact its been around for 70 years and seems very solid... I have heard from friends and neighbors, that almost (almost is the key word...and assumption) 7 to 15 years they had to replace new boilers... Pigtail, Ptol (cleaned) burner model and control... thank you!

LS123

SteamingatMohawk

Keeping it consistent is a perfectly good reason and historically rewarding. Thumbs up!

Jamie Hall

First thing to do is to determine whether the pressuretrol is in the power circuit to the burner or a 24 volt circuit. It could be either.

Then to find the low water cutoff.

Whichever circuit it's in, what is wanted is that the two safety controls are wired in series, so that if either one is open (tripped) no current can flow in the circuit.

This may take some serious sleuthing -- since there are no usable colour codes. I'd probably start at the pressuretrol -- having found out what voltage it's operating on! -- and first trace the conduit from it to wherever. Then disconnect one -- and only one -- of the two wires at it, and go to the other end of the conduit and figure out which wire at that end is the disconnected one at the pressuretrol. Reconnect that and do the same for the other one (you're going to need a multimeter or a test light). Then start at the distant end of that conduit, and figure out which wire connects to what. And follow on along, step by step, until you reach the burner or a transformer or a power supply.

Do all this with the power to the boiler turned off...

At each step make a diagram! And label the wire ends in some unmistakable way!

Now you will have created a circuit diagram and wiring plan for the system -- and the question now is, do you need to fix anything? If not, I'd make sure it was all put back together and works -- and file the diagrams. However, if you find actually damaged wires or connectors, you may want to replace that section of conduit.

If the circuit diagram you make doesn't make much sense, try posting a picture of it and we'll see what we can do.

SteamingatMohawk

Thanks @Jamie Hall I learned something.

LS123

Thank you @Jamie Hall et al.

Jamie I will try what you suggested in a little bit ...

Oh nooooo ... I jinxed myself... since the water pressure was not showing up after I cleaned up the pig tail... I figured I will double check to see why I dont see the pressure gauge moving to PSI showing on the boiler... I guessed I had tighten the pig tail little too mach.... this time it broke... some threads are inside the metal ring... I have to run to the local shop and get a pig tail....

See attached...lol... Using a pipe extractor 1/4 should be ok? or should I just let it be...

By the way although boiler had 1 psi... there is very little... I mean I can hardly see any steam coming out of it.. It being where the pigtail was the hexagon thing... Is that how it suppose to be?



..
. pigtail needed replacement anyways....

LS123

I still dont understand why there is not significant amount of steam NOT coming out of the hole where the pigtail was... I bypass all and burner runs fine, there are steam about 1 PSI and radiators are hot... I send a friend out to get the pig tail so I can keep an eye on the boiler...just in case all of a sudden steam start coming out....

LS123

Hello all... got the pig tail back on, also wiring is done and tested... works perfectly... thank you all.. and thanks @Jamie Hall !

Jamie Hall

Bravo!

Steamhead

How about a pic of the boiler itself?

LS123

Goiod morning @Steamhead this is sorted now... but I forgot to respond to a question from @SteamingatMohawk... in regards to wiring, all wires on this system (wire going to the burner, and pressuretrol) were connected to 115V, 15A circuit of its own on the circuit board (only wire 24v is the thermostat cable)

EdTheHeaterMan

@Jamie Hall @LS123 I read that you have all the limits on the 120V circuit. GOOD!

Oil fired boilers should have all the limits on the 120V side of the control system. A "shorted wire" in a low voltage system will not allow the burner to stop. although the term "shorted wire" is not the correct term, it is easily understood. If the low voltage wire becomes overheated for any reason and the insulation is compromised, that connection of the wires may actually jump the TT terminals on the primary control, eliminating all the safety devices and even the thermostat in some cases.

I believe this is part of the Fire code, or the electrical code, or both. I can't remember because I learned this over 40 years ago. It is one of those things I just know.

So from the burner switch to the burner, there should be enclosed in the metal covered wire, a Hot and a Common or Neutral or what everyone refers to as the "White Wire". This way if the insulation melts, then the fuse or circuit breaker will trip and you won't have a runaway burner

Starting at the burner switch, thru the metal conduit, the hot (or black wire) should make a stop at all the limit controls. The burner emergency switch is usually first on the path, then the LWCO followed by the Pressure troll, and finally to the protecto-relay (aka Primary control)

Diagram

LS123

@EdTheHeaterMan thank you so much for this infor... very insightful...