RVP 6536 SERIES, Service Manual

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operation of both 1
st
and 2
nd
stage units. However, if when
powering both systems from the on-board generator and the
cooling demand does not require that both systems operate,
stage two will shut down leaving stage one in operation.
Heat operation always energizes both stages, however, only
stage one operates if power is not available to circuit #2.
B. Thermostat
This thermostat is designed to operate 12 VDC controlled
heating and air conditioning systems. It can control one stage
of heating and two stages of cooling. It is a manual
changeover type of thermostat between heating and cooling.
Manual changeover indicates that the operator must manually
switch the thermostat from cooling operation to heating. The
thermostat will not make this change automatically. It also
incorporates time delay circuitry. The user selectable heating
mode on the sub-base allows gas heat control or heat pump
operation.
The time delays amount to 3 minutes between off and on
cycles. Thirty seconds of this time delay is at the turn on of
the compressors. This is to allow time for generators to
stabilize when initially starting. The balance of the delay (2.5
minutes) occurs when the compressors cycle off. This is to
allow time for the air conditioner pressures to balance before
restarting. This delay will eliminate problems associated with
short cycling and will extend equipment life. There is thirty
seconds and two degrees between 1
st
and 2
nd
stage cooling.
The thermostat will not call for 2
nd
stage cooling until room
temperature rises 2 degrees above the 1
st
stage starting
temperature. Once the thermostat calls for 2
nd
stage cooling,
a 30 second delay is incurred to prevent both stages from
starting together.
The operating setpoints are changeable to suit the comfort
needs of the occupants. Instructions for setting operating
temperatures (the setpoints) are covered in “Adjusting
Setpoint”.
7. THERMOSTAT CONTROL PANEL
A. OPERATION
Your air conditioner is operated from the control panel
located on the electronic wall mounted thermostat. When the
furnace is connected to this thermostat, it will be operated
from the same control panel.
Identification and operational descriptions for all control
panel switches and display are listed below:
1. Liquid Crystal Display - We will start with the
display because the display will be visible any time
the system is in operation. The display will remain
visible while the thermostat is on and powered.
2. System Switch - The system switch has four
positions to control the operation of the heating and
air conditioning systems. They are as follows:
COOL - When in the cool position, 1
st
and 2
nd
stage
cooling will cycle from the cooling system setpoint.
Blower operation will be controlled by the position
of the Cooling Fan Switch.
HEAT - When in the heat position, the heating
system will cycle from the heating system setpoint.
Heat will be by electricity (heat pump) or gas as
selected on sub-base. The gas heating blower will
operate per the heating system manufacturer
specifications.
OFF - When in the off position, no thermostat or
system operation will occur.
FAN - When in the fan position, the cooling blower
will operate continuously at high speed.