Date: Fri, 26 Nov 2010 02:20:26 -0500
From: Roger <sub1@rogerhalstead.com>
Subject: Re: [Amps] MOVs
Some where around here I think I might still have one of those 50,000
joule MOVs and they are big. They are mounted on their own aluminum
back plate. IIRC they are about 2.5 X 3.5 X about 1" thick.
73
Roger (K8RI)
## IF I remember correctly, the MOV's in those Josyln units are
aprx 2" square x 3/4" thick. Telco's used em by the thousands.
The 3 phase ones had 3 x movs and 3 x neons. The single phase
240/120 v had just 2 x movs and 2 x neons. In all cases, the mov's
are wired from each hot to neutral. On a typ 208/120 vac 3 phase
set up... the same 130-140 V rated movs are used and wired the same
way, hot to neutral.
## 90% of our telco sites are 208/120 vac. The small stuff out in the
field is 240/120 single phase. The real big offices are all 480/277 vac ..
or 600/ 346 vac.
## I see home depot, et all sell smaller versions, designed to connect
to your main 200A panel, and usually through a 40-60A breaker position.
The mov's inside em are mot as big as the ones Josyln uses, but are no where
near the price tag either. Installing a medium to large one..to your
200A main panel is a good idea, and works very well, as a primary
device to protect most of the transients coming in off the street. In some
counties/states. .. [ I believe parts of Florida], insurance co's will
stipulate
that they must be installed, and functioning at all times. Insurance co's
were getting weary of paying out huge claims for blown up fridge compressor's
tv's, and everything else in the home.
A good PI type 120 vac filter..down stream, like the better quality 4-6 x
outlet type box's... we used at work for pc's etc, are good too. These are
the
ones that had the giant torroids and caps in em..making up PI filters in each
leg.
These also had the usual myriad of big mov's in em too.
later.... Jim VE7RF
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