new to forum/ and have a question

[wam57]

I have been in the plumbing and heating field for 35 years, presently retired. I started out doing residential work in the early 70's then progressed on to large commercial work. So when it comes to modern home heating units I'm a little behind, maybe a lot behind who knows. But here is my problem;

I am going to install a burnham alpine 105 boiler in my home. I have been reading the instructions and I am confused by a statement regarding CROSS PHASING when it comes to hooking up the T T terminals to existing solenoid valves does anyone know what this means?
Thanks in advance.

[paul52446m]

I have been in the plumbing and heating field for 35 years, presently retired. I started out doing residential work in the early 70's then progressed on to large commercial work. So when it comes to modern home heating units I'm a little behind, maybe a lot behind who knows. But here is my problem;

I am going to install a burnham alpine 105 boiler in my home. I have been reading the instructions and I am confused by a statement regarding CROSS PHASING when it comes to hooking up the T T terminals to existing solenoid valves does anyone know what this means?
Thanks in advance.

Hi Paul here. Well i am about the same as you 40 years heating and boilers, but not a lot of commercial in boilers I think the cross phasing, just means, don't cross your hot and ground. On most electronic boards they will not work right if you cross the hot and ground wires , and you also need the earth ground.
Do you have just a two wire stat? I don't get into the Hi Eff boilers.
I do 80+ and a little lo and hi pressure steam. Paul

[wam57]

cross phasing

thanks Paul. My name is Mike. I have 2 wire stats. 3 stats total and 3 automag valves. It's funny cause I asked 2 electricians and 2 hvac contractors and they all said they never heard of this (cross phasing) except on 3 phase electric systems not on 24 volt. I don't want to burn anything out. 1 man did tell me what you have said but he wasn't sure. May have to call Burnham. Thanks again.

[paul52446m]

thanks Paul. My name is Mike. I have 2 wire stats. 3 stats total and 3 automag valves. It's funny cause I asked 2 electricians and 2 hvac contractors and they all said they never heard of this (cross phasing) except on 3 phase electric systems not on 24 volt. I don't want to burn anything out. 1 man did tell me what you have said but he wasn't sure. May have to call Burnham. Thanks again.

I am not familiar with your valves, but i think what they are talking about is like
wiring up zone valves. You know how important it is in 24 volt wiring to keep hot to hot and not cross, because the other side of transformer goes to ground, Also we know we can't wire two transformer together. I have seen a lot of electricians get messed up on low volt wiring. Paul

[paul52446m]

I am not familiar with your valves, but i think what they are talking about is like
wiring up zone valves. You know how important it is in 24 volt wiring to keep hot to hot and not cross, because the other side of transformer goes to ground, Also we know we can't wire two transformer together. I have seen a lot of electricians get messed up on low volt wiring. Paul

i am sure you have diagrams, i was just looking at this.
AUTOMAG - Technical Information

Paul

[dfitz3390]

I believe you are correct Paul, recently i attended a controls class and the instructor kept stressing the importance of not cross phase/reverse polarity on modern controls. ( low or hi voltage )
In addition, making sure you keep the furnace/boiler on its own circuit and grounding correctly back to the panel will eliminate problems.

[paul52446m]

I believe you are correct Paul, recently i attended a controls class and the instructor kept stressing the importance of not cross phase/reverse polarity on modern controls. ( low or hi voltage )
In addition, making sure you keep the furnace/boiler on its own circuit and grounding correctly back to the panel will eliminate problems.

I am 65 yr,s old and there has been a lot of changes over the years going from
pictorial wiring diagrams to somatic, to ladder. I know when i trained my service
man ten years ago, the most important courses are identifying controls and reading wiring diagrams. Paul

[Edward12]

Cross phasing

This just means that the 24 volts portion of the control board is reversed polarity and screws up the operation. Usually this will affect the ignition rectification in high efficiency units. Most circuit boards will tell you with it's led code when this happens. It's not much to worry about. The only thing you would need to do is reverse the polarity by swapping 24 volt leads coming out of the transformer to the board. The problem you would worry about is crossing the 24 volt wire creating a direct short or connecting two transformers together. Hope this answers you question.


heatandcooldiy.com

[HayZee518]

control wiring

on most hvac systems and heating systems, one side of the 24 volt control transformer is tied to earth ground, as a true neutral. the other side is always hot. if the circuit board has one side of its input intentionally grounded through a wire or screw to earth ground, reversing the control transformer's leads will cause problems. make sure your control wiring color codes are the same. i.e. the x2 lead is say, a low voltage "white" then the grounded connection on the circuit board should also be a low voltage "white." we're talking something like an #18 ga insulated wire.

[rmw]

Most of the high efficiency boilers are sensitive to stray voltage on the controll boards so they simply want a dry contact open or closed no power flowing from any source other than the control. So you may have to install a relay so TT is just a dry contact.