Re: FCC Approval for Automatic Transfer Switch

In article <1179967215.284773.322390@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>,
<bbawkon@xxxxxxxxxxxx> wrote:
Hello Everyone,

I've searched and searched, but I just can't seem to come up with a
solid answer. I've asked quite a few people that I consider
knowledgeable about FCC Part 68, but I've got some VERY mixed answers
to my question. I'm hoping someone here can at least point me in the
right direction - even if you can't clear up the murky waters.

We're designing an automatic PSTN Failover device. It's basically a
DPDT relay connected to a micro-controller. The micro-controller is
connected to a PBX, and if the PBX Fails, the uC switches the relay so
that a different PBX can take over the line. This is a BIT
simplified, but the relays (I believe) are the only important part of
the equation anyway.

What we need to know, is what FCC rules will govern our device? Does
it even have to be FCC approved since it doesn't have any electrical
circuits in the PSTN line?

Any help, or pointers to FCC rules would be HIGHLY appreciated.

The infamous "Part 68" _will_ apply. it is a device 'directly connected'
to the PSTN. Is there a 'failure mode' of the relay (e.g. damaged insulation)
that 'could' result in 'something else' (e.g. the relay 'power' circuit)
getting on the phone wires?

You can probably find 'certified' relays -- every modem that has an aux
jack for a phone handset has a relay performing -exactly- the same function
as your device -- switching an incoming line between two different CPE.


.