[114857] in North American Network Operators' Group
RE: Why choose 120 volts?
daemon@ATHENA.MIT.EDU (Dave Larter)
Thu May 28 10:44:13 2009
Date: Thu, 28 May 2009 10:44:00 -0400
In-Reply-To: <4A1EA1EA.5030400@templin.org>
From: "Dave Larter" <dave@stayonline.com>
To: "Pete Templin" <petelists@templin.org>
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
I was referring to, when a 120v device is attached to the 5-15 end of
the cord. On the inside of these grounded devices I often find that the
neutral is tied to ground. So in the case of the c14 being connected to
a 240v PDU when I 120v device is connected it will ground one of the
load lines. And yes, voltage will drop while current spikes, thus
tripping the breaker.=20
-----Original Message-----
From: Pete Templin [mailto:petelists@templin.org]=20
Sent: Thursday, May 28, 2009 10:39 AM
To: Dave Larter
Cc: nanog@nanog.org
Subject: Re: Why choose 120 volts?
Dave Larter wrote:
> Seems like if the c14 was connected to a 240v PDU the 5-15 would
> deliver 240v to the equipment, arc/pop tripping the breaker on the
> PDU as soon as it is connected killing power to everything on that
> PDU. Or am I missing something?
If you plug a PDU into a service that's higher voltage than expected,=20
why would the PDU circuit breaker trip? That breaker is measuring=20
current, AFAICT, though in the end it might be measuring power.=20
Regardless, it isn't measuring voltage, because that isn't constant=20
(it's AC, after all) and is likely to drop under a short circuit, not=20
skyrocket like the current will.
pt
