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I installed an Ecosmart 27kw tankless water heater yesterday and as far as heating the water goes, everything works perfectly.

The issue is when the water heater is running, I lose internet!

Specs:

• Heater is 240v 27kw @ draw 112.5amps


• Breakers are 3x 40amp dual pole across both sides of the split phase


• Wiring is 3x 8awg


• My internet is 10mbit ADSL down the phone line.

--

My suspicion is that the high amp lines are creating an electrical field which is interfering with the low voltage phone line system, killing my internet.

When turning on the hot water, I loose access to ping google.com, however I can still ping 192.168.2.1 [my router] which says it's not the router that's being interfered with via power loss.

Any recommendations regarding minimum distance between the high amp cables and the phone line. Am I even on the right track here?

Thanks - Jon

UPDATE

Thanks for the input from everyone - I've been able to narrow this down to a single breaker. 1 of 3 causes the internet to die when turned on. For now I've got it turned off, and I'm getting 2 of 3 heating elements working which will suffice for the short term. See here for a video explaining exactly what's happening. Whenever B1 is turned on, the internet dies:

https://photos.app.goo.gl/53R1jaZqjEg9WwVC9

First, make sure that your three supply cables are paired properly. The unit has 3 heaters internally. There are several ways cables could be crossed that would result in power from 1 heater coming up one cable and returning on another cable. The heater would work properly, but would kick stupid large amounts of EMF from the two imbalanced cables. Just double-check it.

Or, the heater may be throwing high frequency electromagnetic hash, with the cable(s) becoming antennas and making this worse. Now, electric resistive heating elements, alone, do not throw electromagnetic hash. That would only happen from

• a) control electronics, which will surely only be on one cable/circuit; or


• b) power choppers ("dimmers") which could be on 1 or all of the circuits, but there'd be no useful reason to have them on more than 1 circuit.

Also, there's a thing I don't like about how Ecosmarts are installed - they expect you to cram three #8 cables through one 1" hole, which violates Code six ways from Sunday. (it would work if you used individual THHN wires through 1" conduit).

I would install a 6" square deep or larger metal box right below the EcoSmart and a short EMT conduit nipple connecting it to the EcoSmart's wiring hole. Bring the 3 cables into the large box with correct, legal clamps; leaving space for up to 3 "surge suppressors" to be fit onto 3 knockouts.

Then I would consult with EcoSmart and ask them a) which circuit powers the control electronics and b) whether they merely switch all 3 heaters, or whether they use power choppers, and if they do, on which circuit(s).

On the circuits which do not use choppers or electronics, those can be wired straight through the 6" box, up the conduit nipple and to the terminals.

For the circuit(s) which do use choppers or electronics, you run a pigtail from the EcoSmart's terminal into this box. Then you mount a "surge suppressor" in one of the knockouts (or not, if it's a type that can live inside the junction box e.g. Meanwell SPD-20-277P), and join those wires to the power line from the panel. This creates a "tee" where that circuit powers both the EcoSmart and the surge suppressor. The suppressor goes in parallel to the EcoSmart, it's not wired in series like a switch.

At this point, the surge suppressor(s) should be damping out the EM interference before it leaves the metal faraday cage of the Ecosmart + junction box.

I suppose Ecosmart could build this into the product, but that would raise the price-point, and so you might not have selected the product.

Long shot...if I'm wrong I'll delete.

112 Amps is a HUGE draw. As you probably know, many houses have a total 100 Amp (sometimes less) service. If your service drop isn't significantly larger, or even if it is but the utility didn't provision it well (e.g., they can, as I understand from other questions regarding service-entrance vs. "other" cables for 100A and similar sizes, downsize a good bit based on normal expected usage), then you could have a significant dip every time the heater kicks in. While the DSL modem is likely designed to handle a range of voltages, that still might be enough to cause problems. Similar to the way a laser printer on a 15A circuit can cause enough of a dip to reset some devices or at least to lower voltage enough for a few seconds that a UPS will treat it as an outage.

The right way to test this would be to monitor the voltage on the line powering the DSL modem as the heater starts up. If your voltages drops from 115V to 95V (or something like that) then the modem may simply not handle the low voltage and/or the voltage change well and lose the signal.

The secondary ways to test this are:

• See if lights (especially incandescent as LED will often handle voltage fluctuations just fine) dim when the heater starts up.


• Plug the modem (and while you're at it, the router and any other nearby computer-related devices, except laser printers) into a UPS. I use APC, but any decent model will do fine and I think it is a great investment - one didn't-reboot-during-a-thunderstorm can make it worth it even if it doesn't help for this problem. If the internet stays "live" with the modem & router on a UPS then you have your answer - and your fix.

112A will induce voltages in any cables (phone connections) anywhere near that massive power-line you have.

What is meant by the term "split-phase" - is this single phase or guessing by the use of "3x 40amp dual pole breakers" a system where a 3 phase supply is split into 3 single phases?

If so, I strongly doubt it meets current electrical regulations...