Eco Smart Tankless Water Heater requires two EGCs

[Greg1707]

An Eco Smart Tankless water heater is installed with two or three 40 amp circuits. Two for the smaller unit and three for the larger. The installation instructions specify a separate EGC for each circuit. I saw an installation video on YouTube where the installer used EMT from the panel to the heater. Two 40 amp circuits with two EGCs. Any idea why a ground for each circuit it required?

http://https://www.youtube.com/watch?v=Okzydipeno0

 

[petersonra]

An Eco Smart Tankless water heater is installed with two or three 40 amp circuits. Two for the smaller unit and three for the larger. The installation instructions specify a separate EGC for each circuit. I saw an installation video on YouTube where the installer used EMT from the panel to the heater. Two 40 amp circuits with two EGCs. Any idea why a ground for each circuit it required?

http://https://www.youtube.com/watch?v=Okzydipeno0

probably because that will always work and meet code. most of these things get installed by plumbers and they want to try and make sure the worst case is covered would be my guess.

suppose you run both circuits in the same PVC conduit. by code, you only need run a single EGC.

but if you ran them in separate PVC conduits, you need to run an EGC in each conduit.

it may also be something that was left over from some European instructions.

 

[JFletcher]

Before I watched the video, I would have guessed the components of the heaters were isolated from one another, thus requiring two or three grounds. After watching, idk. mfg specs.

 

[kwired]

Instructions likely assume a cable assembly is being used for each circuit.