Earth Klear Sky 400, Owner'S Manual, Page: 31 / 57

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A Protective Earth, known as an equipment-grounding
conductor in the US National Electrical Code, avoids an
electrical hazard by keeping the exposed conductive
surfaces of the Earth Outdoor furnace and the IBC-3.1 at
earth potential.
To avoid a possible voltage drop, no current is allowed to
flow in this conductor under normal circumstances. Fault
currents will usually trip or blow the fuse or circuit breaker
protecting the circuit. A high impedance line-to-ground
fault insufficient to trip the over current protection may still
trip a residual current device or a ground fault circuit
interrupter (GFCI) if present. Make sure the furnace is
properly grounded withan approved grounding rod. A 15
AMP GFCI may trip the breaker with as low as 6-8 Amps of
power draw. If a GFCI is required, a 20 AMP GFCI is
recommended. Please consult with a local licensed
electrician to determine if the current installation meets
USNE Code.
Failure to do so will void your warranty .
We highly recommend taking a picture of the wiring to the
IBC-3.1 and keeping it on file for future reference, should
the need arise.
IBC-3.1 to External Low Voltage Sensor
Connections
Two sensors are located outside the PCD. A 30k ohm
thermistor is mounted in a thermal well that is set into the
furnace water jacket. This sensor facilitates management of
the water temperature.
An oxygen sensor is mounted into the exhaust steam of the
furnace to insure the proper fuel air mixture for the best
combustion. Two different types of industrial sensors are
used depending on your model and year of manufacturing.
MODEL 150 Wiring Requirements
The Model 150 is wired at the factory. The Model 150