anyone run 240V for servers?

[Phil Marsh]

Thanks Sean,
Indeed, underground service is one more reason to like Fort Collins. I'm
thinking you're correct as far as surge protection being
adequately supplied by the whole-house unit.
Thanks,
Phil

On Mon, Sep 15, 2025 at 10:36 AM Sean Reifschneider <jafo00 at gmail.com>
wrote:

> 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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