Carrier Air Conditioner specifications Start-Up And Operation, Operating Limitations

START-UP AND OPERATION

NOTE: Refer to Start-Up Checklist on pages CL-1 to CL-8.

Actual Start-Up — Actual start-up should be done only under supervision of a qualified refrigeration mechanic.

1.Be sure all service valves are open. Units are shipped from factory with suction, discharge, and liquid line service valves closed.

2.Using the Marquee display, set leaving-fluid set point (CSP.1 is Set Point mode under sub-mode COOL). No cooling range adjustment is necessary.

3.If optional control functions or accessories are being used, the unit must be properly configured. Refer to Op- erating Data section for details.

4.Start chilled fluid pump.

5.Turn ENABLE/OFF/REMOTE CONTACT switch to ENABLE position.

6.Allow unit to operate and confirm that everything is func- tioning properly. Check to see that leaving fluid tempera- ture agrees with leaving set point (CSP.1 or CSP.2), or if reset is used, with the control point (CTPT) in the Run Status mode under the sub-mode VIEW.

Operating Limitations

TEMPERATURES (See Table 35) — If unit is to be used in an area with high solar radiation, mounted position should be such that control box is not exposed to direct solar radiation. Exposure to direct solar radiation could affect the temperature switch controlling cooler heaters.

Table 35 — Temperature Limits for Standard Units

Unbalanced 3-Phase Supply Voltage — Never operate a motor where a phase imbalance between phases is greater than 2%. To determine percent voltage imbalance:

	max voltage deviation
% Voltage Imbalance = 100 x	from avg voltage
	average voltage

The maximum voltage deviation is the largest difference between a voltage measurement across 2 legs and the average across all 3 legs.

Example: Supply voltage is 240-3-60. AB = 243 v

BC = 236 v AC = 238 v

1. Determine average voltage:

243 + 236 + 238

Average voltage =

3

=7173

=239

2.Determine maximum deviation from average voltage:

(AB) 243 – 239 = 4 v (BC) 239 – 236 = 3 v (AC) 239 – 238 = 1 v

Maximum deviation is 4 v.

3.Determine percent voltage imbalance:

TEMPERATURE	F	C
Maximum Ambient Temperature	125	52

% Voltage Imbalance = 100 x

4

Minimum Ambient Temperature	0	–18
Maximum Cooler EWT*	95	35
Maximum Cooler LWT	70	21
Minimum Cooler LWT†	38	3.3

LEGEND

EWT — Entering Fluid (Water) Temperature

LWT — Leaving Fluid (Water) Temperature

*For sustained operation, EWT should not exceed 85 F (29.4 C).

†Unit requires modification below this temperature.

Low-Ambient Operation — If operating temperatures below 0° F (–18 C) are expected, refer to separate installation instruc- tions for low-ambient operation using accessory Motor- master® III control. Contact your Carrier representative for details.

NOTE: Wind baffles and brackets must be field-fabricated for all units using accessory Motormaster III controls to ensure proper cooling cycle operation at low-ambient temperatures. See Installation Instructions shipped with the Motormaster III accessory for more details.

Brine duty application (below 38 F [3.3 C] LCWT) for chiller normally requires factory modification. Contact your Carrier representative for applicable LCWT range for standard water-cooled chiller in a specific application.

VOLTAGE

Main Power Supply — Minimum and maximum acceptable supply voltages are listed in the Installation Instructions.

239

= 1.7%

This voltage imbalance is satisfactory as it is below the maximum allowable of 2%.

IMPORTANT: If the supply voltage phase imbalance is more than 2%, contact your local electric utility com- pany immediately. Do not operate unit until imbalance condition is corrected.

Control Circuit Power — Electronic control includes logic to detect low control circuit voltage. Acceptable voltage ranges are shown in the Installation Instructions.

MINIMUM FLUID LOOP VOLUME — To obtain proper temperature control, loop fluid volume must be at least 3 gal- lons per ton (3.25 L per kW) of chiller nominal capacity for air conditioning and at least 6 gallons per ton (6.5 L per kW) for process applications or systems that must operate at low ambi- ent temperatures (below 32 F [0° C]). Refer to application information in Product Data literature for details.

FLOW RATE REQUIREMENTS — Standard chillers should be applied with nominal flow rates approximating those listed in Table 36. Higher or lower flow rates are permissible to obtain lower or higher temperature rises. Minimum flow rates must be exceeded to assure turbulent flow and proper heat transfer in the cooler.

Operation below minimum flow rate could subject tubes to frost pinching in tube sheet, resulting in failure of cooler.

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