Case Studies

The emergency power
generator protection circuit
breaker problem started during
tests of the emergenc
y system
.
The first thing facilities did was
bring both the installing
c
ontractor and elevator equip-
ment manufacturer back in, but
none of their suggestions had
any affect.
The contractor suggested
increasing the circuit breaker
trip settings
. That didn
’t work,
and the fac
ilities manager
wasn’t willing to increase the
settings any further. If a build-
ing power emergenc
y oc
curred
now, the elevator system
wouldn’t operate! The manager
asked his ow
n team to c
onduct
a power quality survey of the
whole elevator emergenc
y elec
-
trical distribution system and
pinpoint the problem once and
for all.
Application Note
A large c
ommerc
ial building
had just finished an elevator
equipment upgrade — but they
hadn’t been able to bring the
elevator back into normal oper
-
ation. For some reason,
whenever the emergency
power generator was called on
to supply energ
y, its protection
circuit breaker would trip.
The upgrade was intended to
bring the original DC elevator
up to a state-of-the-art system,
w
ith better elevator control,
operation, energy efficiency,
reduced maintenance costs, and
tenant satisfaction. Despite all
the efforts some problems were
still unresolved.
Elevator trips emergency
generator breaker
From the Fluke Digital Library @ www.fluke.com/library
Measuring tools: Fluke 434 Power
Quality Analyzer
Features: V, A, Hz, Transients, Inrush
Power
Quality
Case
Study
Measurements
Facilities used a three-phase
Power Quality Analyzer to
examine the elevator system
’s
operating characteristics during
an emergency power system
test. First, they connected the
analy
zer to the c
ircuit and used
the setup function to make
sure all the connections were
accurate.