5.10Evaporator Fan Motor Removal

a. Shut off unit main power supply.

WARNING

Lock open and tag unit disconnect before working on fan motor. Remove fuses and take them with you after noting this on tag.

CAUTION

Before attempting to remove fan motors or motor mounts, place a piece of plywood over evaporator coils to prevent coil damage.

b. Loosen motor hold down bolts on mounting bracket so that fan belt can be removed. Motor power wires need not be disconnected from motor terminals be- fore motor is removed from unit.

c. Loosen but do not remove the 2 motor mounting bracket bolts on left side of bracket.

d. Slide motor/bracket assembly to extreme right, re- move bolts and lift out through space between fan scroll and side. Rest motor on a high platform such as a step ladder. Do not allow motor to hang by its power wires.

5.11Pressure Relief Device

All units are equipped with a fusible-plug type safety relief device on the refrigerant tubing. The relief setting is 197 _F to 203 _F on all units.

5.12Crankcase Heater

A crankcase heater is supplied on the 008 & 012 size units and on all 134a units. The heater prevents liquid refrigerant from accumulating in the compressor crankcase during extended shutdown periods. Heater is automatically energized whenever unit main power is on and compressor is stopped. Heater is de-energized when compressor starts.

Do not shut off main power supply for an extended period except for servicing unit. Turn on power supply for at least 24 hours after an extended shutdown before starting compressor. Refer to “Operation”.

5.13Cycle--LocTM-- Protection Device

All units are equipped with Cycle-LOC current-sensing lockout relay. This device will lock out the compressor after any safety trip (discharge pressure switch, suction-pressure switch, or internal overload of the compressor). Check reason for lockout before resetting the device. Refer to unit label wiring diagram. To reset, turn the system switch to OFF, then back to COOL.

5.14Discharge and Suction Pressure Switches

Refer to Table 1 through Table 2 for opening and closing settings for these safety devices.

The discharge pressure switch is located on the compressor on the 008 & 012 size units and on the discharge line on all other units. The suction pressure switch is located on top of the compressor on 06DR compressor equipped units and on the suction line on all other units.

5.15Oil Charge

All units are factory charged with oil. On 06D compressors, observe the oil level in the sight glass at start-up. If unit oil level is below sight glass, add oil until level reaches approximately 1/4 sight glass.

If oil charge is above sight glass, do not remove any oil until the compressor crankcase heater has been energized for at least 24 hours.

When additional oil or a complete charge is required, use only the following Carrier approved oil.

R-22 Units

Design Series One 204/206 size units Witco part number 999-5170-55

Design Series One 208/212 size units and all Design Series Two

Witco - Suniso 3GS

Calumet - RO-15

R-134a Units

Castrol - Icematic E68

ICI - Emkarate RL68HP

R-407C Units

004 and 006

Copeland Ultra 22CC

 

Mobil Artic EAL 22CC

 

ICI (Virginia KMP) Emkarate

 

RL32C

 

Thermal Zone 22CC

 

 

008 and 012

Castrol - Icematic E68

 

ICI - Emkarate RL68HP

 

 

 

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Carrier 90MA/MF/MU manual 134a Units

90MA/MF/MU specifications

The Carrier 90MA/MF/MU series represents a significant advancement in HVAC technology, designed for commercial applications needing reliability, efficiency, and precision in climate control. These units are renowned for their ability to cater to varying thermal loads while minimizing energy consumption, making them an ideal choice for various settings including offices, retail spaces, and industrial facilities.

One of the standout features of the Carrier 90MA/MF/MU series is its impressive energy efficiency. The equipment is designed with advanced thermodynamic principles to ensure maximum heat transfer and minimal energy loss. With high Seasonal Energy Efficiency Ratios (SEER) and Energy Efficiency Ratios (EER), these units help building owners achieve higher energy savings compared to traditional HVAC systems.

Another significant characteristic of the 90MA/MF/MU series is the integration of advanced control technologies. The units come equipped with sophisticated microprocessor-based controls that allow for precise temperature management and enhance overall system performance. Features like modulating capabilities and variable speed fans provide superior comfort levels by continuously adjusting to the changing environmental conditions.

The 90MA series also emphasizes quiet operation, which is critical for commercial environments. The innovative design includes insulation and vibration dampening technologies that reduce noise levels, ensuring a comfortable working atmosphere.

Durability and reliability are also central to the design of the Carrier 90MA/MF/MU series. These units are engineered with high-quality materials and components, including robust compressors and corrosion-resistant finishes that withstand harsh weather conditions. This durability extends the lifespan of the units, thus reducing maintenance costs and downtime.

In terms of versatility, the 90MA/MF/MU series offers a broad range of configurations and options, including various sizes and capacities. This flexibility allows for tailored solutions that meet the specific needs of different applications, from large commercial buildings to smaller retail outlets.

The series also supports environmentally friendly refrigerants that comply with global standards, marking Carrier’s commitment to sustainable practices. This approach not only reduces environmental impact but also positions businesses favorably in the eyes of eco-conscious consumers.

Overall, the Carrier 90MA/MF/MU series stands out as a pinnacle of efficiency, performance, and reliability in the commercial HVAC market. Its advanced technologies and thoughtful design cater to the diverse needs of modern businesses while promoting a sustainable and comfortable indoor environment.