Step 5 — wire low voltage connections – Carrier 50PEC09-18 User Manual

Page 25

Table 2 — Electrical Data — 50PEC Units

LEGEND

Make all final electrical connections with a length of flexi-

ble conduit to minimize vibration and sound transmission to

the building.
SUPPLY VOLTAGE — Operating voltage to unit must be

within voltage range indicated on unit nameplate.
EXTERNAL LOOP POWER CONNECTION — If the unit

will be connected to an external loop pump or flow controller,

connect the pump to the loop pump terminal block PB1. The

maximum power handling is 4 amps at 240-v. The pumps will

automatically cycle as required by the unit.
220-V OPERATION — All 220/240-v units are factory-

wired for 240-v. The transformer wiring may be switched for

220-v operation (as illustrated on the wiring diagrams) by

switching the RED and ORG leads at L1.

Step 5 — Wire Low Voltage Connections

WATER FREEZE PROTECTION — The Aquazone™ con-

trol allows the field selection of source fluid freeze protection

points through jumpers. The factory setting of jumper JW3

(FP1) is set for water at –1.1 C. In earth loop applications,

jumper JW3 should be clipped to change the setting to 12.2 C

when using antifreeze in colder earth loop applications. See

Fig. 25.

ACCESSORY CONNECTIONS — Terminal labeled A on

the control is provided to control accessory devices such as

water valves, electronic air cleaners, humidifiers, etc. This

signal operates with the compressor terminal. See Fig. 26.

Refer to the specific unit wiring schematic for details.
NOTE: The A terminal should only be used with 24-v signals

— not line voltage signals.

WATER SOLENOID VALVES — An external solenoid

valve(s) should be used on ground water installations to shut

off flow to the unit when the compressor is not operating. A

slow closing valve may be required to help reduce water

hammer. Figure 26 shows typical wiring for a 24-vac external

solenoid valve. Figures 27 and 28 illustrate typical slow closing

water control valve wiring for Taco 500 Series and Taco ESP

Series valves. Slow closing valves take approximately 60 sec.

to open (very little water will flow before 45 sec.). Once fully

open, an end switch allows the compressor to be energized (on-

ly on valves with end switches). Only relay or triac based elec-

tronic thermostats should be used with slow closing valves.

When wired as shown, the slow closing valve will operate

properly with the following notations:

1. The valve will remain open during a unit lockout.
2. The valve will draw approximately 25 to 35 VA through

the “Y” signal of the thermostat.

50PEC

UNIT SIZE

VOLTAGE

CODE

V-Ph-Hz

MIN/MAX

VOLTAGE

COMPRESSOR

FAN MOTOR

FLA

TOTAL UNIT

FLA

MIN CIRCUIT

AMPS

MAX FUSE/

HACR

QTY

RLA

LRA

220/240-1-50

198-264

3.2

0.4

3.6

4.4

15.0

220/240-1-50

198-264

4.0

0.4

4.4

5.4

15.0

220/240-1-50

198-264

4.7

0.6

5.3

6.5

15.0

220/240-1-50

198-264

5.6

0.6

6.2

7.6

15.0

FLA

— Full Load Amps

HACR — Heating, Air Conditioning and Refrigeration
LRA

— Locked Rotor Amps

RLA

— Rated Load Amps

AQUAZONE CONTROL (Complete C Control Shown)

Fig. 25 — Typical Aquazone Control Board

Jumper Locations

a50-7467tf

IMPORTANT: Connecting a water solenoid valve can

overheat the anticipators of electromechanical thermo-

stats. Only use relay based electronic thermostats.

Typical

Water

Valve

24 VAC

Terminal Strip

Fig. 26 — Typical Aquazone Accessory Wiring

Fig. 27 — AMV Valve Wiring

THERMOSTAT

AMV

TACO VALVE

HEATER SWITCH

a50-8441