Dielectric fitting question on my Garn

[Sawyer]

Are dielectric unions used only where copper joins the black pipe or must they be used if after a bronze fitting there is copper located anywhere in the system? I will have black iron 10' from the Garn, then only black iron or brass fittings between the Garn and the pex tubing. I will however have copper 200' at the end of the pex tubing connecting the heat exchanger to the pex supply and return lines.

It seems counter productive to add copper by way of a dielectric fitting which is half copper, and then the copper fitting to revert back to black iron which will continue to the pex. Without additional information is seems better to use an iron fitting and avoid the copper.

 

[pybyr]

In my opinion, which is not based on professional training, but rather, the physics and chemistry of galvanic action, I'd keep it all iron on the Garn end of the PEX, and treat the long PEX run between the iron and the copper as its own (i.e. the PEX) splendidly long dielectric fitting.

Let us know what you arrive at and how/ why.

Good luck

 

[heaterman]

I personally never use them on a Garn. .....or any other wood boiler for that matter. The blasted things ALWAYS wind up leaking. We do however limit the copper tube in the near boiler piping as much as possible and prefer to use all steel. When you get your Garn piped up, get your self a ground rod and drive it into an area that has good moist soil (under the eave of your house is a good place) then bond the piping and the Garn to the rod with some bare copper ground wire.

 

[Jim K in PA]

George - do as heaterman suggested. I ran a heavy ground wire from the lug for the electric element cover on the front of the GARN to the ground rod for my garage. Fortunately, the ground rod was about 6' away from the front face of my GARN.

 

[Tony H]

I was told by a couple different pro plumbers only use them where copper and black pipe connect and not when brass pipe is used .

 

[Sawyer]

Thanks for the replies, your input and experience is appreciated. I will do as suggested; it seems to be the sensible solution.

I will stay with all black pipe other than the brass fittings on the near side piping.

I will drive two ground rods (sandy soil) and ground the Garn to them.

 

[Frozen Canuck]

Just a suggestion George as we also have sandy soil here 65' of it around the river bank area, we always use a grounding plate say 24" x 24" buried at the bottom of open trench. Gives you way more contact with the ground. Contact a local electrician for their opinion on this method.

 

[Sawyer]

Just a suggestion George as we also have sandy soil here 65' of it around the river bank area, we always use a grounding plate say 24" x 24" buried at the bottom of open trench. Gives you way more contact with the ground. Contact a local electrician for their opinion on this method.

Good idea, I will check with a neighbor up the lake who is an electrician. A good ground is very important.

 

[pybyr]

Have you trenched and buried your underground pipe yet? When I had some drainage work done for my house, I got about 8 ft of large gauge uninsulated copper and put it in the bottom of the trench before it was backfilled, and had the house end connect to my electric service entrance, which, in turn, is bonded to everything else that's grounded (phone network interface, etc). In your case, if the trenching is still ahead for you (I don't recall), you could have the same buried copper run tie into your heat system at both ends; that way, both are grounded and also tied together.

 

[Sawyer]

Have you trenched and buried your underground pipe yet? When I had some drainage work done for my house, I got about 8 ft of large gauge uninsulated copper and put it in the bottom of the trench before it was backfilled, and had the house end connect to my electric service entrance, which, in turn, is bonded to everything else that's grounded (phone network interface, etc). In your case, if the trenching is still ahead for you (I don't recall), you could have the same buried copper run tie into your heat system at both ends; that way, both are grounded and also tied together.

Unfortunately Trevor, my pipe is in the ground. I do have some uninsulated 4/0 copper wire that I could place in a trench or create a coil in a hole. All I have to do is wait for a little more snow to melt so I can get to the backhoe and have the frost leave that area. At the temps we are having in WI that time may be earlier than usual.

 

[Frozen Canuck]

Just a short cautionary note on the copper below grade as a ground. This would not be allowed according to code here, only ferrous metals meet code here for that purpose. Check with your neighbor electrician re: code requirements in your area. Also our code specifies braided/stranded copper wire as opposed to solid wire as well as guage of wire based on the load (size of service) that is grounded, we are also required to leave the cable shield on except where it connects to the grounding plate & to the load to protect the cable from physical damage & corrosion as well as contact with a live load, make sure you ask him about these considerations too. Better safe than...well...the other end of the stick.

 

[Sawyer]

Just a short cautionary note on the copper below grade as a ground. This would not be allowed according to code here, only ferrous metals meet code here for that purpose. Check with your neighbor electrician re: code requirements in your area. Also our code specifies braided/stranded copper wire as opposed to solid wire as well as guage of wire based on the load (size of service) that is grounded, we are also required to leave the cable shield on except where it connects to the grounding plate & to the load to protect the cable from physical damage & corrosion as well as contact with a live load, make sure you ask him about these considerations too. Better safe than...well...the other end of the stick.

I will ask Matt about your questions, perhaps that piece of diamond plate 3'x3' that has been kicked around for years will be the best option. Insulated braided copper wire sized to the load is required here also for the same reasons.