Safari motorhome TREK 2005, Instructions Manual

Page: 273 / 330

TREK 2005 Electrical System - House --- Section 8 • 273
Circuit Breaker
Branch circuit breakers supply AC power to the different items or “loads.” Should a breaker “trip”
from over current use or a short circuit condition, the load should be tested or disconnected to determine
the reason the breaker tripped. If no cause is found (or not readily apparent) reset the breaker by
switching the breaker to the
OFF position, then back to ON . Should the breaker trip again after the load
is re-applied, there may be a fault with that particular load. Do not continue to reset breaker until the
problem has been diagnosed and corrected.
The internal configuration of the circuit breaker is designed to trip when excess current causes the
breaker to heat up. The trip action of the circuit breaker can occur within milliseconds due to the speed
at which electricity can travel. Breakers are designed to operate at a continuous load of 80% of the
breaker’s rated capacity. For example: A breaker with a 20 Amp rating will operate a continuous 16 Amp
load. This design leaves a small amount of working capacity within the breaker. When an inductive load
is applied, such as when an electric motor turns on, the motor starts to spin and current consumption may
momentarily exceed the rated capacity of the breaker. As the electric motor comes up to operating speed,
the electric motor’s current consumption will decrease. The AC current load then falls back into the
breaker’s rated 80% set point. This electric principle should be kept in mind when using anything other
than 50 Amp shore service and using appliances with electric motors, such as air conditioners. When
using outlets, care should be considered when applying loads such as electric motors, heaters, coffee
makers, toasters, hair dryers or other large current consuming loads. The current rating is usually stated
on most electrical items. The current rating will either be rated in amps or watts. Current ratings stated
on electrical items will change slightly with voltage fluctuations. As voltage increases, current consumption
decreases. As voltage decreases, current consumption increases. This may explain why in some instances
items operated at borderline voltage to current tolerances may seem fine in one location but problematic
in another.
NOTE:
To calculate watts to amps simply divide the watt figure by the voltage of which the
item operates from. For example: The electrical item is rated at 1370 watts. Divide
that by the operating voltage of 115 Volts which equals 11.913 Amps. Use this formula
to calculate the amount of load to the available power supply.