I think all safety concerns are addressed in
current POE standard and, based on our objectives, it will not change in POE
plus:
Safety standards of information technology
equipments consider following hazards:
1. Electric
shock
We are addressing it in
POE by keeping voltage to be SELV
2. Energy related hazards
Hazardous energy level: A
stored energy of 20J or more, or available continuous power level
240 VA or more.
To meet stored energy requirements
at 57V, output capacitance of PSE and input capacitance on PS should be below 12000uF.
(1/2xCxV^2 =20J). Therefore we meet stored energy requirements and definitely 240VA
power level.
3. Fire hazards
We are addressing this
issue by keeping POE output to comply with limited power source requirements
(LPS) (Pout <100VA and Iout <150/Vout for inherently limited
POE and Pout< 250VA for non inherently limited POE)
4. Heat related hazards
Clause 6.3 of UL 60950
provides guideline for protection of the telecommunication wiring from
overheating.
We are not intend to have
even close to 1.3A per conductor in POE plus, therefore we comply
with this requirements too.
5. Mechanical hazards
Not relevant to POE
6. Radiation hazards
Not relevant to POE
7. Chemical hazards
Not relevant to POE
Conclusion: All safety
requirements of information technology equipments addressed in current POE standard
and POE plus objectives.
Regards
Arkadiy Peker
System Architect
PowerDsine, Inc.
1865 New Highway
Tel. 631-756-4680 x404,
Fax. 631-756-4691
Arkadiyp@xxxxxxxxxxxxxxxxx
From:
owner-stds-802-3-poep@xxxxxxxx [mailto:owner-stds-802-3-poep@xxxxxxxx] On Behalf Of Michael McCormack
Sent: Tuesday, February 01, 2005
2:38 PM
To:
STDS-802-3-POEP@xxxxxxxxxxxxxxxxx
Subject: Re: [8023-POEP] Cabling
and wire current capacities
Removing my chairman's cap for a moment and expressing
my personal opinions:
1)
I am not intent on supporting outside wiring and I did not see anyone at the
meeting who was pushing it (I may have missed though I was present 99.9%). As
such I would say the PHYs of EFM will not get consideration.
2)
If anything that is being suggested means my equipment can no longer push it as
SELV, I am against it. I do not believe that the voltages, amperages or
wattages that have been proposed push us beyond (or even close to) surpassing
SELV.
3)
No one can anticipate every bad installation practice and correct for it in a
specification. Had the installer who tie wrapped the CAT5e cables to the
steam pipe tied them the to the furnace stove piping they would have combusted
with or without power. I would not say bury our heads in the sand; but,
the idiots often prove too resourceful to be thwarted at every turn.
Cheers
Mike
(just
a guy from a systems vendor)