Low Voltage Transformers and Inrush Current
As a leader in low voltage landscape lighting, Hadco has years of experience
with transformers. Recently, we have had instances of house circuit breakers
tripping when our low voltage transformers are turned on. Other low voltage
transformer manufacturers we spoke with are also experiencing the same
House circuit breakers can trip because of high initial peak inrush current.
Inrush current occurs when inductive loads, such as low voltage transformers,
are first turned on. Remember years ago when your house lights would dim
whenever your refrigerator’s motor first turned on? That was due
to inrush current. Inrush current can be many times higher than steady-state
current and can, therefore, trip the house circuit breaker.
Hadco has dramatically reduced the potential of circuit breaker trip
by installing a surge suppressor in all of our 22 volt HO transformers.
In rare cases, the house circuit breaker may still trip depending upon
the age of the breaker, total amperage load on the breaker, or total load
on the transformer. It is recommended that the circuit breaker be changed
to one rated to guard against inrush current, such as Square D’s
HOMELINE® HOM-HM high magnetic series, catalog numbers HOM115HM (15
Amp) and HOM120HM (20 Amp), or an equivalent breaker by another reputable