Rheem RKNL-B073CL15E, Manual, Page: 6 / 80

Air
Unit Features & Benefits
RKNL-B Series
6
Also inside the blower compart-
ment is the low-ambient control
(
), low-pressure switch ( ),
high-pressure switch ( ) and
freeze stat refrigerant safety
device (
). The low-ambient
control allows for operation of the
compressor down to 0 degrees
ambient temperature by cycling
the outdoor fans on high pres-
sure. The high-pressure switch
will shut off the compressors if
pressures in excess of 610 PSIG
are detected, this may occur if
the outdoor fan motor fails. The
low-pressure switch shuts off the
compressors if low pressure is
detected due to loss of charge.
The freeze stat protects the com-
pressor if the evapora tor coil gets
too cold (below freezing) due to
low airflow. Each factory-installed option is brazed into the
appropriate high or low side and wired appropriately. Use of polar-
ized plugs and sharder fittings allow for easy field installation.
Inside the blower compartment the interlaced evaporator can
also be viewed. The evaporator uses enhanced fin technology
for maximum heat transfer. The TXV metering device assures
even distribution of refrigerant throughout the evaporator. (Note:
the single stage 6 utilizes orifices).
Wiring throughout the unit is neatly bundled and routed. Where
wire harnesses go through the condenser bulkhead or blower
deck, a molded wire harness assembly (
) provides an air-tight
and water-tight seal, and provides strain relief. Care is also taken
to tuck raw edges of insulation behind sheet metal to improve
indoor air quality.
The furnace compartment contains the latest furnace technology
on the market. The draft inducers (
) draw the flame from the
Rheem exclusive in-shot burners ( ) into the aluminized tubular
heat exchanger ( ) for clean, efficient gas heat. Stainless steel
heat exchangers can be factory installed for those applications
that have high fresh-air requirements, or applications in corrosive
environments. Each furnace is equipment with a two-stage gas
valve (
), which provides two stages of gas heat input. The first
stage operates at 50% of the second stage (full fire). 81% steady
state efficiency is maintained on both first and second stage by
staging the multiple inducers to optimize the combustion airflow
and maintain a near stioceometric burn at each stage.
The direct spark igniter ( ) assures reliable ignition in the most
adverse conditions. This is coupled with remote flame sense ( )
to assure that the flame has carried across the entire length of the
burner assembly. Gas supply can be routed from the side or up
through the base.
Each furnace has the following safety devices to assure consis-
tent and reliable operation after ignition:
• Pressures switches (
) to assure adequate combustion airflow
before ignition.
• Rollout switches ( ) to assure no obstruction or cracks in the
heat exchanger.
• A limit device that protects the furnace from over-temperature
problems.
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