Start Up
38
RT-SVX26K-EN
2. After the compressor and condenser fan have started
and operated for approximately 30 minutes, observe
the operating pressures. Compare the operating
pressures to the operating pressure curve in the
Service Facts.
3. Check system subcooling. Follow the instruction listed
on the subcooling charging curve in the Service Facts.
4. Repeat
Step 1
through
Step 3
for each refrigerant
circuit.
5. To stop the SERVICE TEST, turn the main power
disconnect switch to the “Off” position or proceed to
the next component start-up procedure. Remove
electro mechanical test mode connections (if
applicable).
Dehumidification Option
Momentarily jump across the Test 1 and Test 2 terminals of
the LTB1 until the unit enters test mode 7. (
Table 12, p. 36
)
Once the unit is in the reheat test mode, verify that the
three-way valve has shifted to the reheat position and that
the supply temperature rises 10°F more than when in
cooling mode stage 2. Monitor the suction pressure for 15
minutes. The suction pressure should remain within 5 psi
of normal cooling operation.
Heating Start-Up
Open the main disconnect switch to shut the unit off and
to reset the RTRM.
Follow the Test Guide in
Table 12, p. 36
to start the unit in
the heating mode. ReliaTel Control Momentarily jump
across the Test 1 and Test 2 terminals on LTB1 one
additional time if continuing from previous component
start-up or until the desired start-up component Test is
started.
Note:
At initial start-up modulating gas heat exchangers
can produce a resonance that will subside after the
break-in period.
Variable Air Volume Applications
(Multi-zone, Traditional VAV)
Supply Air Temperature Control -
Occupied Cooling and Heating
The RTRM is designed to maintain a selectable supply air
temperature of 40ºF to 80ºF with a +/- 3.5ºF deadband. To
reduce the risk of coil freezing, it is not recommended to
set the supply air temperature below 50ºF. In cooling
mode, if the supply air temperature is more than 3.5ºF
warmer than the selected temperature, a stage of cooling
will be turned ‘on’ (if available). Also, if the supply air
temperature is more than 3.5ºF cooler than the selected
temperature, a stage of cooling will be turned ‘off’. At very
low airflow, the unit may cycle stages ‘on’ and ‘off’ to
maintain an average discharge air temperature outside the
7 degrees deadband.
If the unit has modulating gas heat, it can be made to
discharge heating with VAV control. This is done by
placing a contact closure across the ‘Changeover Input’ on
the RTAM. While in the mode, the unit will heat to the
Supply Air Heating Se/- 3.5ºF. During low loads, or
low airflow conditions, the actual temperature swing of
the discharge air will likely be greater.
The RTRM utilizes a proportional and integral control
scheme with the integration occurring when the supply air
temperature is outside the deadband. As long as the
supply air temperature is within the setpoint deadband,
the system is considered to be satisfied and no staging up
or down will occur.
Supply Duct Static Pressure Control
The supply duct static pressure is measured by a
transducer with a 0.25 to 2.125 Vdc proportional output
which corresponds to an adjustable supply duct static
pressure of 0.3" w.c. to 2.5" w.c. respectively with a
deadband adjustment range from 0.2" w.c. to 1.0" w.c. The
setpoint is adjustable on the RTAM Static Pressure
Setpoint potentiometer or through ICS.
Example:
Supply Duct Static Setpoint = 2.0" w.c.
(RTAM) deadband = 0.2" w.c. (RTAM)
Duct Static Control Range = 1.9" w.c. to 2.1" w.c.
Table 14. POE Oil recharge amount (fl. oz.)
Model
C1
25mm/18mm
C2
25mm/18mm
YS*150
56/105.6
62/99.2
YH*150
56
38
YH*150 Reheat
56
56
YS*180/155
112/182.4
62 (62)/96
YH*180
102
52
YH*180 Reheat
56
56
YSH210, YS*175
112/182.4
38 (62)/96
YS*210/175
112
38 (62)
YH*210
114
52
YH*210 Reheat
102
56
YS*240/200
112
56
YH*240
112
56
YH*240 Reheat
112
112
YS*300/250
112
106
YH*300
112
56
