Clean Air Coil; Set Blower Motor Speed; Constant Torque (Ecm) Motor; Constant Airflow (Ecm) Motor - Carrier Aquazone 50PTH024 Installation, Start-Up And Service Instructions Manual

Fig. 33 — Aquastat for Boilerless Control
1. Check the electrical fusing/breaker and wiring for the correct
size.
2. Verify that the low voltage wiring between the thermostat or
DDC controls and the unit is correct.
3. Verify that the water piping is complete and correct.
4. Verify that there are no leaks in the external piping or in the
internal unit piping. Correct as necessary.
5. Verify that the isolation or flow control valves are open and
that any automatic flow control valve or balancing valve are
set to the correct setting.
6. Check that the water flow is correct and adjust if necessary.
7. Check the blower for free rotation, and that it is secured to the
shaft.
8. Verify that the foam blower shipping support has been
removed.
9. Vertical Units Only:
Verify that vibration isolation has been provided and that the
unit has been installed on a solid structure.
10. Horizontal Units Only:
Verify that the hanging brackets have been installed and that
the unit is secured to an adequate support structure.
11. Verify that the unit has proper service clearance. Be certain
that all access panels are secured in place.
12. Verify that ductwork has been properly fastened to supply
and return duct collars.
13. Verify that the ductwork is free from obstruction and that all
dampers or registers are open.
14. Make sure return air filters are positioned correctly in the fil-
ter rack if removed during installation.
15. Verify that the unit is not in TEST mode.
16. Verify that all control components have been properly config-
ured and that all control components have been wired.
17. For units with WSHP Open, verify that a ZS sensor, WS sen-
sor, Equipment Touch
installed and that a commissioning interface is available.

CLEAN AIR COIL

To obtain maximum performance, clean the air coil before starting
the unit. A ten percent solution of dishwasher detergent and water
is recommended for both sides of the coil. Rinse thoroughly with
water.
™ , or System Touch ™ has been

Set Blower Motor Speed

CONSTANT TORQUE (ECM) MOTOR

The 50PT units from size 015 to 070 in 208-v, 230-v, 265-v, or
460-v are available with constant torque ECM blower motors.
Constant Torque ECM motors have five speed settings. See
Table 9 for the factory default motor setting. See Table 10 for
blower performance by speed setting.
If a motor speed change is required, follow the instructions below:
1. Disconnect power to the heat pump and follow all proper
lockout and tagout procedures to ensure that power is
removed from the unit.
2. Remove the blower access panel and access the torque tap
wire on the motor.
3. Change the torque tap wire to on the molex plug to one of the
five speed settings. (See Fig. 34.)
YL
1
OR
2
PU
3
BL
4
BR
5
GY
9
Fig. 34 — Constant Torque ECM Pin Diagram
NOTE: Constant Torque Motors (ECM) are programmed to have
a 30s ramp up/down. Contact application engineering for details
on applications where immediate ramp down is required.

CONSTANT AIRFLOW (ECM) MOTOR

50PT units from size 015 to 070 in 208-v, 230-v, 265-v, or 460-v
are available with a constant airflow ECM blower motor. These
motors dynamically adjust their power output to precisely match
the desired airflow on a pre-programed fan curve. See Table 10 for
Constant Airflow ECM Motor Blower performance data. These
motors include the following features:
1. Three Speed Settings: Units are factory set to "NORM" but
can be field adjusted to "+" to increase cfm by 15% or to "-"
to reduce cfm by 15%. See the constant airflow ECM motor
blower performance table for complete details on available
cfm for each unit size (refer to Step 9 — Wire Control Con-
nections section on page 33.)
2. Low cfm Ventilation: Units circulate air at 70% of full airflow
rate when there is a call for fan only.
3. Passive Dehumidification: Reduces airflow during a cooling
call when dehumidification is also required. This reduces the
sensible heat ratio of the cooling coil and extends cooling run
time to dehumidify more effectively (refer to Step 9 — Wire
Control Connections section on page 33.).
4. Test Mode: Operates the motor at a 70% torque setting. This
setting can be used to diagnose programming problems in the
motor itself (refer to Step 9 — Wire Control Connections sec-
tion on page 33.).
5. cfm Indicator Light: indicator light blinks for each 100 cfm of
air delivered.
NOTE: This blink code is approximate and should not replace test
and balance.
36
P20-1-SPD1
P20-2-SPD2
P20-3-SPD3
P20-4-SPD4
P20-5-SPD5
P20-6-COM