Surge Protector Circuit Questions



Hello,

I'm hoping someone that's knowledgeable about surge protectors can
answer this:

I opened the case of an industrial power strip (PDU) to see what's in
it.
Basically, the PCB inside just has the Line, Ground, and Neutral wires
soldered onto the PCB, and then 3 other matching L-G-N wires soldered
on to continue on to the receptacles.
On the PCB, in parallel to thse main L-G-N traces, are 3 surge
protection circuits, each circuit consisting of 1 fuse, 1 thermal cut
off (TCO), and 3 MOVs.
All 3 surge circuits connect in the classic arrangement of several MOVs
in parallel placed across each of the three conductive pairs; L-N, L-G,
and N-G.

I understand the arrangement of MOVs, thermal cut offs (TCOs), and
fuses, but have 2 questions:

1)
The fuses are 2AG-224 8A 125V Fast-Acting.
Why was an 8A fuse picked?
Since the fuse is there for the case when the MOVs have failed closed
and the surge circuit is always drawing current, wouldn't a lower rated
fuse be preferred?

2)
The traces in the surge circuits are anywhere from .1" to .3" wide.
The PDU is rated 20A.
Shouldn't the traces be at least .5" wide?
For example, what happens if a surge strikes while the PDU has
equipment plugged in that is drawing 18A?
Wouldn't that burn out or blast a trace path?

Thank you,
Lou

.



Relevant Pages

  • Re: Just had a thought about surge suppressors...
    ... This causes an internal fuse or circuit breaker to open, ... protect the load from a surge, unless the overvoltage is such that it ... disconnect a grossly undersized protector even faster, ... exactly where that surge energy must be diverted to: earth ground. ...
    (alt.home.repair)
  • Re: Power Conditioners?
    ... the fuse died in vain. ... but the equipment plugged into it was ... Same applies to surge protectors. ... Reason number one for why a blown protector did nothing. ...
    (rec.music.classical.recordings)
  • Fuses, was Re: FARK OFF - CRITICAL IDIOLOGUE!!
    ... Many kinds of "slow blow" fuse exist made with various and ingenious ... longest current surge. ... resistance of the particular transformer, plus the resistance of the AC ... of a lot of energy to charge large caps. ...
    (rec.audio.tubes)
  • Re: Fuses, was Re: FARK OFF - CRITICAL IDIOLOGUE!!
    ... When this *max* peak current value is flowing in the primary, ... the same primary surge due to core saturation will ... With SS diodes and large value un-charged electros, two kinds of surge go on ... the AC fuse. ...
    (rec.audio.tubes)
  • Re: FUCK OFF - CRIMINAL IDIOT !!
    ... Many kinds of "slow blow" fuse exist made with various and ingenious ... when the switch closes. ... longest current surge. ... resistance of the particular transformer, plus the resistance of the AC ...
    (rec.audio.tubes)