Re: DSC FSA-410AST Smoke Detectors

[Chris <chriswheeldon@xxxxxxxxx>]

On Wednesday, August 21, 2013 4:41:45 AM UTC-7, NickMark wrote:
> On Tuesday, August 20, 2013 6:30:03 PM UTC-4, Chris wrote:
>=20
> > I was looking at the specs for the DSC FSA-410AST smoke detector today,=
 as I have a customer who needs his 8 smokes replaced on a DSC 5010.  I was=
 concerned about moving them to a PGM to allow for keypad reset, as it may =
not provide enough current.  I was a bit surprised to find the following:
>=20
> >=20
>=20
> >=20
>=20
> >=20
>=20
> > Maximum Standby Current: 12=CE=BCA@12 or 24 VDC
>=20
> >=20
>=20
> > Maximum Alarm Current: 25mA - 90mA
>=20
> >=20
>=20
> >=20
>=20
> >=20
>=20
> > The maximum alarm current depends on which specific model you're lookin=
g at, and they have a chart for that... so that's fine.
>=20
> >=20
>=20
> >=20
>=20
> >=20
>=20
> > However... 12=CE=BCA of standby current?  Really?  That means I could p=
ower 25,000 smokes on a 300mA PGM output.  This sounds like a typo to me.  =
Perhaps it was supposed to be 12mA?
>=20
> >=20
>=20
> >=20
>=20
> >=20
>=20
> > Either way, it looks like 8 smokes on a PGM will be fine.
>=20
> >=20
>=20
> >=20
>=20
> >=20
>=20
> > - Chris
>=20
>=20
>=20
> Standby current really is that low on many smokes  not a typo problem is =
when they go in alarm and more than one does  to make sure there is enough =
current to handle it.


Thanks Nick.  I see a lot of old systems that were never planned out well e=
nough and end up with issues (like half a dozen 20-watt sirens trying to dr=
aw way more power than the panel can give).  Actually, this is one of those=
 "problem systems" in another way.  There's a zone expander on the system, =
which is an improvement over most that I see, but the 8 smokes take up only=
 2 zones.  I was hoping they were all home run and could be separated, but =
no... they were all daisy chained instead.

This is a DSC 5010, so it's capable of having two more zone expanders and r=
unning 32 zones.  There's lots of room in the electrical room where the pan=
el is located to add a separate enclosure for the zone expander if needed. =
 And to top it off, this was a prewired building (sometime in the 90's I as=
sume).  So why not home run everything and do it properly?

- Chris