What wire do I need?

[kuribo]

I am about to begin construction of a small outbuilding that will be the home for my Econoburn boiler. I will be trenching and foaming the pex lines to and from the house (where I will locate the 1000 gallons of pressurized storage) and am wondering what type of wire I need to run in the trench from the house to the boiler. There will be two pumps and perhaps a zone valve for the heat dump. Besides the electrical power feed for the boiler, pumps, and valve, what type of cable do I need to run for controls, thermostats, temp sensors, etc.?

Thanks!

 

[SIERRADMAX]

Everything is controlled by the unit itself, including the 115V dump zone. Loss of power dump zone should be adjacent, overhead to your econoburn. You can run another 14/2 wire back to the house for the overheat dump zone or install a transformer and run low voltage wire to your zone valve (depending on voltage). Best thing is to stick an empty 1" conduit in the ground.

 

[BoilerMan]

As an electrician, I'd run some 12-2 UF (direct burial cable) and a 3/4 or one inch PVC conduit for anything else. I never bury 14 gauge due to the "added factor". Meaning that people tent to want more than just a boiler (and system) and a light in the building. Eventually, you'll have more load on the underground feed so the price for #12 is well spent, outside flood light etc. If you ever think you'd want to have an outside light controlled from inside, run 12-3 and your conduit as well.

TS

 

[kuribo]

Thanks for the replies, but what I am asking about is the low voltage, non-power wiring for thermocouples, valve and pump controls. What kind of wire is used for that?

 

[BoilerMan]

For your telemetry (low voltage signals) you can run CAT-5 or simmilar. It depends on how far your run is. What if the distance from the sensors to the utilization equiptment that needs the inputs? Thermocouples and what not do not travel well as they are milivolt signals. Generally you have your equiptment that uses those type of signals in the boiler room and then it talks on a netowrk or converts that into a standard signal (4-20ma, 1-10Volt) or simple open and closure of contacts. You may only need some 18ga twisted pair or simple thermostat wire (bell wire).

Bottom line: How far is the run and what type of signals? Just bury the conduit and put a pull string in it, or suck it through with a shop-vac later.

TS

 

[kuribo]

The underground run is about 50 feet. I will need to send control signals to the pumps and zone valve (for heat dump). I have a roll of cat 5, sounds like that will work...Thanks again...

 

[BoilerMan]

Just double-up the pairs to make it basically 4 wires instead of 8.

TS