18
MOTORMASTER® V CONTROL INSTALLATION
(48TM025 Only)
Install Field-Fabricated Wind Baffles — Wind baffles must
be field-fabricated for all units to ensure proper cooling cycle
operation at low ambient temperatures. See Fig. 22 for baffle
details. Use 20-gage, galvanized sheet metal, or similar
corrosion-resistant metal for baffles. Use field-supplied screws
to attach baffles to unit. Screws should be 1/4-in. diameter and
5/8-in. long. Drill required screw holes for mounting baffles.
Install Motormaster V Controls — The Motormaster V
(MMV) control is a motor speed control device which adjusts
condenser fan motor speed in response to declining liquid
refrigerant pressure. A properly applied Motormaster V control
extends the operating range of air-conditioning systems and
permits operation at lower outdoor ambient temperatures.
The minimum ambient temperatures at which the unit will
operate are:
To operate down to the ambient temperatures listed,
Motormaster V controls (Fig. 24) must be added. Field-
fabricated and installed wind baffles are also required for all units
(see Fig. 22). The Motormaster V control permits operation of
the unit to an ambient temperature of –20 F (–29 C). The control
regulates the speed of 3-phase fan motors that are compatible
with the control. These motors are factory installed.
See Table 6 for the Motormaster V control accessory
package usage. Table 7 shows applicable voltages and motors.
Replacement of fan motor IS NOT REQUIRED ON
CURRENT PRODUCTION UNITS since the control is
compatible with the factory-installed fan motors. Only field
wiring control is required.
Install the Motormaster V control per instructions supplied
with accessory.
Table 6 — Motormaster V Control Package Usage
Table 7 — Applicable Voltages and Motors
To avoid damage to the refrigerant coils and electrical com-
ponents, use recommended screw sizes only. Use care
when drilling holes.
TEMPERATURE OPERATING LIMITS — F° (C°)
Standard
Unit
Unit with
Low Ambient Kit
Unit with
MMV Control
40 (4) 25 (–4) –20 (–29)
UNIT VOLTAGE ITEM DESCRIPTION
48TM016-028
208/230 CRLOWAMB015A00
460 CRLOWAMB016A00
575 CRLOWAMB017A00
VOLTAGE COMPATIBLE MOTOR
208/230-3-60 HD52AK654
460-3-60 HD52AK654
575-3-60 HD52GE576
Fig. 24 — Motormaster® V Control
256 2
12 13A
13B 13C
123
TO MOTOR(S)
TO PRESSURE
TRANSDUCER
BLK
YEL
BLU
FROM FUSE BLOCK
B