Application Note

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Application Note

From the Fluke Digital Library @ www.fluke.com/library

Electronics in your building

don’t like power problems

Lightning strikes,

power loss/generator testing,

utility problems

In my role as a senior project technician I spend a lot of time

in buildings diagnosing problems. My responsibilities involve

electronic controls on HVAC equipment. I also try to help the

customer by diagnosing common problems with other

equipment, which might include telephone systems, elevators,

security equipment, and life safety systems.

Admittedly, while working on

problems with these various

systems I can be a little slow

to note a common denomina-

tor. But over a period of time

I have noticed something that

Prevalence of electronics

It does not take a genius to

recognize that almost every major

subsystem in today’s commer-

cial buildings has some type of

solid-state electronics package

installed. Virtually every HVAC

unit purchased today has an

electronics board in the control

panel. Ditto for security, fire,

and life-safety systems. Digital

telephone and computer network

systems are the same. Regard-

less of system type, the common

element is the electronics.

Another factor in this elec-

tronics equation is that there are

“old” electronics and “new” elec-

tronics. Some electronic systems

in today’s building equipment

were installed 20 or more years

ago, and are even more suscep-

tible to problems.

All of the electronic systems

mentioned above can have

problems due to power. Many

electronics and device manu-

facturers will claim an amount

of tolerance to power problems.

Many will say that a fault due

to power “should not” happen.

Unfortunately the nice tech

support folks on the other end

of the telephone are not stuck

on an elevator or listening to

the fire alarms going off after a

thunderstorm.

Typical power scenarios

Anyone working in a field utiliz-

ing electronics in a building

should be able to easily recog-

nize the scenarios that affect the

power to the electronics. These

scenarios typically are very

repetitive in the building and in

some cases occur frequently.

repeats itself over and over

again—problems due to power!

Approximately 25 to 35 percent

of the service calls I get are

related somehow to a power

issue of one type or another.

A communications card can be easily damaged by incoming power problems. Burn marks

on the electronics and a burning smell are indicators.

By Ron Auvil

Summary of content (3 pages)

PAGE 1
Electronics in your building don’t like power problems Lightning strikes, power loss/generator testing, utility problems Application Note By Ron Auvil Prevalence of electronics In my role as a senior project technician I spend a lot of time in buildings diagnosing problems. My responsibilities involve electronic controls on HVAC equipment.
PAGE 2
Lightning strike One of the most common scenarios is a lightning strike. The prevalence of this problem will depend greatly on your location and climate. I happen to live in the southeastern United States, which is famous for summer thunderstorms in the afternoon. My personal rule of thumb is that after a thunderstorm moves through I will get at least one or two calls from a building that are lightning-related.
PAGE 3
generators start. This may cause electronic circuit problems. It is not uncommon that one percent of electronic devices have some kind of problem after the generator test is performed. If a system is critical a small UPS is installed at the electronic device power supply. In this way the device does not really ever see a power failure. Another advantage of some UPS systems is that they may also provide some surge protection.