anyone run 240V for servers?

[Sean Reifschneider]

If you have whole-house surge protection, I can't see why you would need
another one.  I am in Fort Collins and have underground power service, and
really don't worry about surge protection, but depending on where you are
it may be a bigger deal.  Typical residential power is supplied on two 120v
legs with a neutral, and you get 240 volts by using both of the 120v lines,
because they are out of phase they provide 240v potential across the two
(for 120v power you go either of the hot legs to neutral).  This is why the
breaker uses two panel slots (dual breaker), because it needs to protect
two 120v hot legs.

If you have surge protection on both of those legs for your whole house,
you're probably doing pretty good there.

That said, I have run 240v for machines at home in the past, and I didn't
do any surge protection.

On Sun, Sep 14, 2025 at 11:24 PM Phil Marsh <microcraftx at gmail.com> wrote:

> Hi,
> I'm now trying to run my servers in my rack from a newly-installed 240V
> circuit. Code required a GFCI 240 dual breaker since this is in my basement.
> I have a whole-house battery backup so I don't need a UPS, just a surge
> protector. I do have a whole-house surge protector but not sure if this is
> enough?
> I would like to get NEMA 6-20 or 6-15 outlet surge protectors. I tried
> these:
> https://www.amazon.com/dp/B07SS77B9Q?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1
> but it appears that they were not tested by the manufacturer on GFCI 240V
> NEMA 6-20 circuits and therefore trip the GFCI protection randomly. Any
> imbalance between the two hot wires' currents will trip the GFCI protection
> and I suspect these surge suppressors are doing that because I don't see
> this problem when my equipment is plugged directly into the 6-20, 240V
> outlets.
> Do you think the whole-house surge protector is good enough?
> Does anyone here run 240V in their personal servers and if so, how did you
> handle this? thanks
> Thanks,
> Phil
>
>
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