Installation, Operation and Maintenance Manual : 036-1011(0806)
Page 18
OPERATION
SOUND POWER RATINGS
A sound power level is a measure of the total noise radiated by the machine in all
directions. It is a property of the machine and is essentially independent of the
measuring environment. Sound power levels are useful to equipment manufacturers,
buyers, installers, and users for :
•
Calculating the sound pressure level from a machine at a given distance in a given
environment.
•
Comparing the noise output from different machines.
•
Setting specifications for the maximum permitted noise from a machine.
•
Comparing machines before and after modifications to reduce the noise.
Sound power is measured in watts or picowatts, and sound power levels are traditionally
given in decibels (dB re 1pW). Refer table 8 for sound power level of whole unit and
table 9 for sound power levels of fan only.
TABLE 8 : SOUND POWER LEVELS (DMS SABER UNITS)
TABLE 9 : SOUND POWER LEVELS (STANDARD FANS)
VOLT FREE CONTACT
All Saber units are supplied with Volt free contact, Refer to Electrical wiring schematic
that are pasted inside the unit.
SEQUENCE OF OPERATIONS OVERVIEW
For these units, the thermostat makes a circuit between “R” and “Y1” for the first stage
of cooling. The call is passed to the unit control board (UCB), which then determines
whether the requested operation is available and, if so, which components to energize.
For electric heat units, the UCB passes the call to the electric heater. In both cases,
when the “W1” call is sensed, the indoor air blower is energized following a specified
heating delay. If at any time a call for both heating and cooling are present, the heating
operation will be performed. If operating, the cooling system is halted as with a
completion of a call for cooling. Heating always takes priority.
COOLING SEQUENCE OF OPERATION
•
CONTINUOUS BLOWER
By setting the room thermostat fan switch to “ON” the supply air blower will operate
continuously.
• INTERMITTENT
BLOWER
With the room thermostat fan
switch set to “AUTO” and the
system switch set to either the
“AUTO” or “HEAT” settings, the
blower is energized whenever a
cooling or heating operation is
requested. The blower is
energized after any specified
delay associated with the
operation. When energized, the
indoor blower has a minimum run
time of 30 seconds. Additionally,
the indoor blower has a delay of
10 seconds between operations.
• NO
OUTDOOR
AIR
OPTIONS
When the thermostat calls for the
first stage of cooling, the low
voltage control circuit from R to YI
& G is completed. For first stage
of cooling, compressor 1,
condenser fan motor 1 & 2 are
energized (In case of 40 & 50 TR,
condenser fan motor 1, 2 & 3 will
energize). After completing the
specified fan on delay for cooling,
the UCB will energize the blower
Motor.
When the thermostat calls for 2
nd
stage of cooling low voltage
control circuit from R to Y2 is
completed, compressor 2 is
energized, provided it has not
been locked out. For third stage
of cooling, low voltage control
circuit from R to Y3 is completed
and compressor 3 and condenser
motor 3 energize. In case of 35
TR models, condenser motor 3 &
4 will energise and in case of 40 &
50 TR only condenser fan motor 4
will be energized.
For fourth stage of cooling (for 50
TR only), low voltage control
circuit from R to Y4 is completed,
Compressor 4 is energized
provided it has not been locked
out. If there is an initial call for 4
stages of cooling, UCB will delay
energizing compressor 2, 3 & 4 by
30 seconds each in order to avoid
power in rush, once the
thermostat has been satisfied it
will de-energize YI, Y2,Y3 & Y4.
NOTE :
Condenser fan motors are
3 only in case of 30 TR models.
CAUTION
HOOK UP EMERGENCY SHUT - OFF BUTTON
