Re: NFPA Code Question

[Nomen Nescio <nobody@xxxxxxxxx>]

Michael Baker said:

>NFPA 72-2002
>4.4.4 Performance and Limitations.
>4.4.4.1 Voltage, Temperature, and Humidity Variation. Equipment shall
>be designed so that it is capable of performing its intended functions
>under the following conditions:
>(1) At 85 percent and at 110 percent of the nameplate primary (main)
>and secondary (standby) input voltage(s)
>(2) At ambient temperatures of 0=B0C (32=B0F) and 49=B0C (120=B0F)
>(3) At a relative humidity of 85 percent and an ambient temperature of
>30=B0C (86=B0F)

These are minimum requirements for the equipment.  They don't have anything=

to do with the installation, since a manufacturer could choose to exceed
these minimum requirements.

>NFPA 72-2002
>4.4.5 Protection of Fire Alarm Control Unit(s). In areas that are not
>continuously occupied, automatic smoke detection shall be provided at
>the location of each fire alarm control unit(s) to provide notification
>of fire at that location.
>Exception:  Where ambient conditions prohibit installation of automatic
>smoke detection, automatic heat detection shall be permitted.

The system in question is a residential system.  This requirement does not
apply here.

>NFPA 72-2002
>5.7.1.8*  Unless specifically designed and listed for the expected
>conditions, smoke detectors shall not be installed if any of the
>following ambient conditions exist:
>(1) Temperature below 0=B0C (32=B0F)
>(2) Temperature above 38=B0C (100=B0F)
>(3) Relative humidity above 93 percent
>(4) Air velocity greater than 1.5 m/sec (300 ft/min)

Again, a smoke detector is not required for equipment protection in a
residential system.  These requirements are irrelevant.

One section you neglected to mention is NEC section 110.26, relating to
spaces around electrical equipment.

Generally, there is a working space requirement of 3 feet in front of the
equipment, which can be waived by special permission for low voltage
equipment.  But there is also a "dedicated equipment space" requirement,
which requires a clear space in front of the equipment that extends from
the floor to 6 feet above the equipment or the structural ceiling,
whichever is less.  This requirement could give an inspector grounds to
reject a panel installed in an attic.

The temperature specs for this panel are 32 degrees to 120 degrees
Fahrenheit,, which might be a problem for some attics.  Panels must be
installed per the manufacturer's specs.

Personally, every time I see a panel installed in an attic or above a drop
ceiling, I figure the installer is a complete asshole, because he's
forgotten that people will have to work on that system, and he's too
goddamn lazy to put the panel in an accessible location.  So I'm on the
electrical inspector's side:  move the panel!  Of course, the inspector is
an idiot when he starts talking about return loops on two-wire smoke
detector loops.

Inspectors may think they're God, but they're not.  They're paid to enforce=

code, not make up their own code as they go along.  The installer should
have asked the inspector to cite the code sections that support his
decision.=20

- badenov