YCAL-SB Millennium™ Air Cooled Liquid Chiller

Available Models & Nominal Cooling Capacities

Cooling capacities at 7 °C leaving chilled liquid and 35 °C ambient.

YORK YCAL-SB Millennium™ air cooled scroll liquid chillers provide chilled liquid for all air conditioning applications. They are completely self-contained and are designed to be located outside on the roof of a building or at ground level. Each unit includes four, five or six hermetic scroll compressors, a liquid cooler, air cooled condensers, and a weather resistant microprocessor control centre, all mounted on a formed steel base.

Features

• High efficiency.
• Electronic Expansion Valves (EEV) fitted as standard.
• Manufactured to ISO 9001/EN 29001.
• Full factory run test.
• Optional acoustic kits.
• Small footprint.
• Two refrigerant circuits.
• Accessible components.
• Microprocessor control with visual display of temperatures and alarms.
• Optional multi-unit sequencer.
• Chiller remote alarm contacts.
• Single power and control supply.
• Optional remote liquid temperature reset.

Benefits

• Low operating costs.
• Enhanced efficiency and improved part load performance.
• High standard of quality control.
• Verifies quality control and ensures that the unit operates satisfactorily prior to delivery.
• Reduced sound levels for low sound applications.
• High capacity design ideal for reduced base area applications.
• System stand-by security.
• Ideal for maintenance operations.
• Simple operation.
• Sequencing up to eight chillers in parallel based on mixed leaving liquid temperature.
• Remote alarm notification.
• Easy to install and minimises site wiring costs.
• Improved operating efficiency at part load and reduced operating costs.

Specification

General

The chillers shall be completely factory assembled with all interconnecting refrigerant piping and wiring ready for field installation. After assembly, the unit shall have a full test run with water flowing through the cooler. The unit shall be pressure tested, evacuated and fully charged with refrigerant and include an initial oil charge. The unit structure is heavy-gauge, galvanised steel coated with baked-on powder paint (Desert Sand (RAL 1019)).

Compressors

The unit shall have hermetic scroll compressors. High efficiency is achieved through a controlled orbit and the use of an advanced scroll geometry. All rotating parts are statically and dynamically balanced. The compressor motors shall have integral protection against overloads. The overload protection will automatically reset. Starting shall be direct on line. The motor terminal boxes shall have IP-54 weather protection. The compressors shall be switched On and Off by the unit microprocessor to provide capacity control. Each compressor is fitted with a crankcase strap heater.

Cooler

The cooler is equipped with a heater controlled by a separate thermostat. The heater provides freeze protection for the cooler down to -29 °C ambient. The cooler is covered with 19 mm flexible, closed-cell, foam insulation. The removable head allows access to the internally enhanced, seamless, copper tubes. Flanged water connections and vent and drain connections are included.

Refrigerant Circuits

Each circuit will use copper refrigerant pipe formed on computer controlled bending machines to reduce the number of brazed joints, resulting in a reliable and leak-resistant system. Liquid line components shall include: a service valve with charging port, a high absorption removable core filter-drier, a sight glass with moisture indicator and service valve. In addition, a combined electronic expansion valve / solenoid valve and suction temperature sensor in each refrigerant circuit provide improved part load performance. The control panel is fitted with all the electrical components to operate the valves. Suction line components shall include: a pressure relief valve, a service valve and a pressure transducer. Suction lines shall be covered with closed-cell insulation. An optional ball valve is available for circuit isolation. Models YCAL0147 to 0253. Discharge lines shall include: a service valve, two high pressure cutout switches, a pressure transducer and a check valve. An optional ball valve (and pressure relief valve) is available to replace the check valve for circuit isolation. Models YCAL0287 to 0377. Discharge lines shall include: a service valve, two high pressure cutout switches and a pressure transducer. An optional ball valve (and pressure relief valve) is available for circuit isolation.

Air Cooled Condensers

The condenser coils shall be seamless copper tubes, arranged in staggered rows, mechanically expanded into corrugated aluminium fins. Integral sub-cooling will be included. Design working pressure of the coils shall be 27.9 barg (405 psig). The condenser fans shall be composed of corrosion resistant aluminium hub and glass fibre reinforced polypropylene composite blades moulded into a low noise aerofoil section. They are designed for maximum efficiency and statically and dynamically balanced for vibration-free operation. They shall be directly driven by independent motors, and positioned for vertical air discharge. The fan guards will be constructed of heavy-gauge, corrosion resistant, coated steel. The fan motors shall be totally enclosed air-over (TEAO), squirrel-cage type. They will feature ball bearings that are double-sealed and permanently lubricated.

Power and Control Panels

All power and controls will be contained in an IP55 cabinet with hinged and lockable outer doors. Power and control sections will be housed in separate enclosures. The power panel shall include: A factory mounted non-fused disconnect switch with external, lockable handle to enable connection of the unit power supply. The disconnect switch can be used to isolate the power for servicing. Factory mounted compressor manual motor starters (to provide overload and short circuit protection). Compressor motor starting contactors. Factory mounted control transformer to convert the unit supply voltage to 115 V - 1 Ø - 50 Hz for the control system. Fan contactors with overload current protection. Customer terminal block for status outputs and chilled liquid pump. All exposed power wiring will be routed through IP66 nonmetallic conduit.

Control Panel

The control panel is fitted with all the electrical components to operate the valves. It includes:

• A Liquid Crystal Display (two display lines of twenty characters per line) with Light Emitting Diode back lighting for outdoor viewing.
• A Colour coded 12-button keypad.
• Customer terminal block for control inputs and liquid flow switch.

Microprocessor Control Capabilities

The microprocessor control system is capable of displaying the following:

• Return and leaving liquid temperature.
• Low leaving liquid temperature cutout setting.
• Low ambient temperature cutout setting.
• Ambient air temperature.
• Metric or Imperial data.
• Discharge and suction pressure cutout settings.
• System discharge and suction pressures.
• Anti-recycle timer status.
• Anti-coincident system start timer condition.
• Compressor run status.
• No cooling load condition.
• Day, date and time.
• Daily start/stop times.
• Holiday status.
• Automatic or manual system lead/lag control.
• Lead system definition.
• Compressor starts & operating hours (each compressor).
• Status of evaporator heater and fan operation.
• Run permissive status.
• Number of compressors running.
• Liquid solenoid valve status.
• Load & unload timer status.
• Water pump status.
• Liquid Temperature Reset via a YORK ISN DDC or Building Automation System (by others).

Display/Print Keys: For display of chilled liquid and ambient air temperatures, system pressures (each circuit), operating hours and starts (each compressor), load and unload timers and cooling demand, liquid pump, evaporator heater, solenoid valve and condenser fan status. Print calls up operating data for the systems and history including time, date and reason for last fault shutdown.

An RS-232 port, in conjunction with a press-to-print button, is provided for hard copy print-outs via a separate printer (by others).

Entry Keys: To program and modify system values.

Setpoints Keys: For programming chilled liquid temperature setpoint and range, remote reset temperature range, daily schedule/holiday for start/stop, manual override for servicing, low and high ambient cutouts, low liquid temperature cutout, low suction pressure cutout, high discharge pressure cutout, and anti-recycle timer (compressor start cycle time).

Unit Keys: To set time and unit options.

Unit ON/OFF switch: To activate or deactivate the unit.

Provisions shall be included for: pumpdown at shutdown; optional remote chilled water temperature reset or up to two steps of demand load limiting (depending on model) from an external building automation system. The operating program will be stored in non-volatile memory (EPROM) to eliminate chiller failure due to AC power failure/battery discharge. Programmed setpoints shall be retained in lithium battery backed RTC memory.

Accessories and Options

Power Options

• Power Factor Correction: Factory mounted passive (static) power factor correction capacitors to correct unit compressor power factors to a target of 0.9 - 0.95 (depending on operating conditions).

Refrigerant Circuit Options

• Low Temperature Glycol (Brine): Vessel design to allow operation with leaving glycol temperatures between -1 °C and -6 °C (Models 0147 to 0253) and between -1 °C and -10 °C (Models 0287 to 0377).
• Softstart (Models 0147 to 0253 only): Factory fitted and wired reduced current softstart on compressor No. 2 of each circuit on models 0147 and 0173 or compressor No. 3 of each circuit on models 0197, 0217 and 0253.
• Isolation Valves: One set of ball valves per refrigerant circuit for isolation. Factory installed valve and pressure relief valve in the high pressure (discharge) and valve in the low pressure (suction) pipework.
• Softstart and Power Factor Correction Combination (Models 0147 to 0253 only): Softstart is factory fitted on compressor no.2 of each circuit of models 0147 and 0173, or compressor No. 3 on each circuit of models 0197, 0217 and 0253. Power factor correction is fitted to remaining compressors without softstart fitted. Power factor correction cannot be fitted to a compressor with softstart fitted.

Control Options

• Low Ambient Kit (Models 0147 to 0253 only): Standard units will operate to -4 °C. This accessory includes all necessary components to permit chiller operation to -18 °C. Note: Models 0287 to 0377 will operate to -18 °C ambient as standard.
• Building Automation System (BAS) Interface: The addition of a factory mounted PCB to accept a 4-20 mA, 0-10 Vdc or contact closure input to reset the leaving chiller liquid temperature from a building automation system. (Cannot be fitted when a Remote Control Panel or Multi-unit Sequence Control is fitted). Note: The standard unit capabilities include remote start-stop, remote water temperature reset via a PWM input signal or up to two steps of demand (load) limiting depending on model. The standard unit control panel can be directly connected to a YORK Building Automated System via the standard on board RS485 communication port.
• Language LCD and Keypad: Spanish, French, German, and Italian unit LCD read-out and keypad available. Standard language is English.
• Remote Control Panel and Wall Adaptor: Field mounted remote control panel (Cannot be fitted when a (BAS) Interface or Multi-unit Sequence Control is fitted).

DX Cooler Options

• 38 mm Insulation: Double thickness insulation provided for enhanced efficiency, and low temperature applications.
• 10.5 bar (150 PSI) DWP Flow Switch: Vapour-proof SPDT switch, -29 °C to 121 °C, with 1" NPT connection for upright mounting in horizontal pipe (field mounted).

Condenser Options

• Copper Fin Condenser Coils: Condenser coils are constructed with copper fins (ASTM 287 Test, after 1500 hours 17% weight loss).
• Gold Epoxy Coated Aluminium Condenser Fins: Offers corrosion resistance in mild seashore locations (ASTM 287 Test, after 1500 hours 7% weight loss).
• Blygold Protective Coating: Recommended for corrosive applications, such as coastal locations where salt spray may hit the condenser fins (ASTM 287 Test, after 1500 hours 0% weight loss).
• High Static Pressure Fans: Fans and motors suitable for high external static conditions.

Sound Options

• Compressor Acoustic Sound Blanket: Each compressor is individually enclosed by an acoustic sound blanket. Models 0147 to 0253 - The sound blankets are made with one layer of acoustical absorbent textile fibre of 15 mm thickness and one layer of anti-vibrating heavy material thickness of 3mm. Both are enclosed by two sheets of welded PVC, reinforced for temperature and UV resistance (factory mounted). Models 0287 to 0377 - The sound blankets are made from a composite of materials giving a total jacket thickness of 15mm with an outer covering of PVC (factory mounted).
• Multi-unit Sequencing: A field mounted Sequencing Control Centre to manage sequencing control of up to eight chillers in parallel based on mixed liquid temperature (interconnecting wiring by others). (Cannot be fitted when a (BAS) Interface or Remote Control Panel is fitted).
• Low Sound Fans: Reduced RPM fan motors and alternative fan selection for low sound applications (factory mounted).
• Dual Speed Fans: Dual speed fans offer a very low sound alternative. Fan operates either in high mode (660rpm) or in low mode (520rpm). Fan speed reduces from high to low mode as head pressure falls, typically when the ambient is less than 25-28 °C depending on model size.

Unit Enclosures

• Wire Enclosure: Welded wire mesh guards mounted on the exterior of the unit (factory mounted).
• Louvered Panels and Wired Guards (Models 0147 to 0253 only): Louvered panels mounted over the exterior condenser coil faces, and welded wire mesh guards mounted around the bottom of the unit (factory mounted).
• Louvered Panels [condenser coils only] (Models 0147 to 0253 only): Louvered panels are mounted over the exterior condenser coil faces on the sides of the unit to visually screen and protect the coils (factory mounted).
• Louvered Panels [full unit] (Models 0147 to 0253 only): Louvered panels over condenser coils and around the bottom of the unit (factory mounted).

Vibration Isolation

• Neoprene Pad Isolators: Recommended for normal installations (field mounted).
• 25 mm Spring Isolators: Level adjustable, spring and cage type isolators for mounting under the unit base rails (field mounted).
• 50 mm Seismic Spring Isolators: Restrained Spring-Flex Mountings incorporate welded steel housing with vertical and horizontal limit stops. Housings designed to withstand a minimum 1.0 g accelerated force in all directions to 50 mm. Level adjustable, deflection may vary slightly by application (field mounted).

Operating Limitations

(1) Table shows minimum water / glycol volume of system

Refrigerant Flow Diagram

The diagram illustrates the refrigerant flow through one circuit. Low-pressure liquid refrigerant enters the cooler and is evaporated and superheated by the heat energy absorbed from the chilled liquid passing through the cooler shell. Low-pressure vapour enters the compressor where pressure and superheat are increased. The high-pressure vapour is fed to the air-cooled condenser coil and fans where the heat is removed. The fully condensed and subcooled liquid passes through the expansion valve where pressure is reduced and further cooling takes place before returning to the cooler.

Selection Guide - Water

Data Required

1. Required cooling capacity.
2. Design chilled liquid entering and leaving temperatures.
3. Design water flow rate if one of the temperatures in item 2 are unknown.
4. Design condenser entering air temperature. This will normally be the design summer ambient air temperature unless location or other factors have an influence.
5. Altitude above sea level.
6. Design Cooler fouling factor.
7. Static pressure resistance against condenser entering and leaving air flow (where ducts, louvres, attenuators, etc., are used) at full unit air volume.

Note: Items 1, 2 and 3 must be linked by the following formulae:

Cooling capacity kW = L/s chilled liquid x °C range / 0.2392

Where: Range = Entering liquid temperature - Leaving liquid temperature.

Chiller Selection Method

1. Determine the correct size of chiller by selecting the model which most closely matches the required capacity at the design conditions of leaving water temperature and entering air temperature (Table 10).
2. Apply the relevant correction factors for fouling factor, altitude and fan application (Tables 3 to 5) to the capacity and power values from the capacity table (Table 10). Ensure the corrected capacity is still sufficient for requirements.
3. Using the corrected capacity of the selected chiller, adjust the design temperature range, or flow rate, to balance the formulae shown in "Data Required".
4. Physical and electrical data can now be determined from Tables 11 and 12.
5. Always re-check that selections fall within the design limitations specified (Table 2).

YCAL Sample Selection - Water Cooling

A R407C chiller is required to cool water from 12 °C to 7 °C having a cooling capacity of 160 kW. Other design conditions applying are: Ambient air entering condenser: 35 °C, Fouling factor: 0.044 m² °C/kW, Altitude: Sea level. From a cursory examination of capacity table 10, a YCAL0173SB gives approximately the required capacity of 162.2 kW. Since no correction factors for fouling or altitude apply, the conditions will be as follows: Cooling capacity: 162.2 kW, Compressor power: 56.7 kW, Water temperature: 12 °C to 7 °C. Water flow rate = 162.2 x 0.2392 = 7.76 L/s. Cooler pressure drop = 17.8 kPa (see Figure 3).

Cooler Pressure Drops

Figure 3 shows Cooler Pressure Drops (kPa) versus Flow Rate (L/s) for various YCAL-SB models. It includes formulas for calculating pressure drop based on flow rate for different model groups.

Figure 3: YCAL-SB Cooler Pressure Drops

Fouling Factors

Table 3: Fouling Factors

Altitude Factors

Table 4: Altitude Factors

Fan Application Factors

A capacity factor of 1.01 and a power factor of 0.992 should be applied when optional copper fin condenser coils are specified.

Table 5: Fan Application Factors

Selection Guide - Glycol (Models 0147 to 0253 only)

Data Required

1. Required cooling capacity.
2. Design chilled liquid entering and leaving temperatures.
3. Design glycol flow rate if one of the temperatures in item 2 are unknown.
4. Design condenser entering air temperature. This will normally be the design summer ambient air temperature unless location or other factors have an influence.
5. Altitude above sea level.
6. Design cooler fouling factor.
7. Static pressure resistance against condenser entering and leaving airflow where ducts, louvres, attenuators, etc., are used, at full unit air flow.

Note: Items 1, 2 and 3 must be linked by the following formulae:

Cooling capacity kW = L/s chilled liquid x °C range / Glycol Factor

Where: Range = Entering liquid temperature - leaving liquid temperature.

Selection Method

1. Determine the correct size of chiller by selecting the model which most closely matches the required capacity at the design conditions of leaving glycol temperature and entering air temperature.
2. Apply the relevant correction factors for fouling factor, altitude and fan application (Tables 3 to 5) and glycol concentration (Table 8), to the capacity and power values from the capacity table (Table 10). Ensure the corrected capacity is still sufficient for requirements.
3. Using the corrected capacity of the selected chiller, adjust the design temperature range, or flow rate, to balance the formulae shown in "Data Required".
4. Physical and electrical data can now be determined from Tables 11 and 12.
5. Always re-check that selections fall within the design limitations specified (Table 2).

YCAL Sample Selection - Glycol Cooling

A R407C chiller is required to cool propylene glycol from 2 °C to -2 °C having a cooling capacity of 160 kW. Other design conditions applying are: Ambient air entering condenser: 30 °C, Fouling factor: 0.088 m² °C/kW, Altitude: 1200 m, Glycol Strength: 29% w/w. For a -2 °C propylene glycol leaving temperature, the recommended concentration from table 7 is 29%. From the capacity table 10, an "Ethylene Glycol" temperature of "-3 °C" leaving chilled liquid temperature (Propylene Glycol capacity = Ethylene Glycol capacity at 1 °C lower temperature) at 30 °C condenser entering air temperature, a YCAL0217SB gives approximately the required capacity of 164.9 kW. From the design fouling factor, corrections of capacity x 0.987 and power x 0.995 apply (Table 3). From the design altitude, corrections of capacity x 0.973 and power x 1.020 apply (Table 4). From the design glycol strength, corrections of capacity x 1.0027 and power x 1.0009 apply (Interpolation from Table 8). The glycol factor is obtained from table 6 using the design leaving liquid temperature and the percentage by weight glycol concentration. Recommended glycol concentrations for the unit are given in table 7. Applying these factors to the selection: YCAL0217SB Cooling Capacity = 164.9 x 0.987 x 0.973 x 1.0027 = 158.8 kW. Compressor Power = 59.7 x 0.995 x 1.02 x 1.0009 = 60.6 kW. For the glycol concentration specified and a leaving liquid temperature of -2 °C, the Glycol Factor is 0.2457 from table 6. The flow rate can be determined, therefore, from the formula shown in "Data Required": 158.8 kW = (2 - (-2)) x Flow (L/s) / 0.2457. Flow rate = 158.8 x 0.2457 / 4 = 9.75 L/s. This satisfies the Operating Limits. Cooler pressure drop = 14.5 kPa (Figure 3) x 1.191 (correction factor, Table 9 for 29% strength). Cooler pressure drop = 17.3 kPa.

Glycol Factors

Table 6: Glycol Factors

Recommended Concentrations

Table 7: Recommended Concentrations

Glycol Concentration Factors

Table 8: Glycol Concentration Factors

Pressure Drop Corrections

Table 9: Pressure Drop Corrections

Cooling Capacities

Water Cooling

Table 10: YCAL-SB Cooling Capacities (Water)

Glycol Cooling (30% Ethylene Glycol)

Table 10: YCAL-SB Cooling Capacities (30% Ethylene Glycol)

Note: Table should also be used for 30% Propylene Glycol after reducing LCLT by 1 °C. (For example the cooling capacity when using -1 °C LCLT using Propylene Glycol is equivalent to -2 °C LCLT using Ethylene Glycol).

Physical Data

(1) Liquid sub-cooling measured at the liquid line should be between 8.5 and 11.0 °C at circuit full load. (1) Sub-cooling is determined by the level of refrigerant charge in each system. (2) Sound Pressure levels are 1 m from the Control Panel, at a height of 1.6 m from the unit base. (2) Levels may vary at different positions around the unit.

Electrical Data

Standard Fan Chillers (950 rpm)

Table 12: Electrical Data - Standard Fan Chillers (950 rpm)

Low Sound Fan Chillers (710 rpm)

Table 12: Electrical Data - Low Sound Fan Chillers (710 rpm)

Dual Speed Fan Chillers (660rpm)

Table 12: Electrical Data - Dual Speed Fan Chillers (660 rpm)

Dual Speed Fan Chillers (520 rpm)

Table 12: Electrical Data - Dual Speed Fan Chillers (520 rpm)

High Head Fans (1410 rpm)

Table 12: Electrical Data - High Head Fans (1410 rpm)

High Head Fans (950 rpm)

Table 12: Electrical Data - High Head Fans (950 rpm)

(1) Nominal Running kW is the power absorbed by the unit at 7°C leaving chilled liquid temperature and 35°C ambient air temperature. (2) Maximum Running kW is the power absorbed by the unit at 13°C leaving chilled liquid temperature and 46°C/45°C ambient air temperature. (3) Nominal Running Amps (with or without Power Factor Correction) is the sum of the compressor running load amps and the fan full load amps. (4) Maximum Running Amps (with or without Power Factor Correction) is the sum of the compressor full load amps and the fan full load amps. (5) Compressor / Fan Starting Amps is the maximum in-rush current per compressor / fan. Currents in brackets are with optional Soft Start fitted. (5) * The compressors fitted to System 2 on model 0197 have a reduced starting current of 120 (78) Amps. (5) ** The compressors fitted to System 2 on model 0347 have a starting current of 226 Amps. Soft Start can only be fitted on compressor No. 2 of each circuit on models 0147 and 0173 or compressor No. 3 of each circuit on models 0197, 0217 and 0253. Power Factor Correction cannot be fitted to a compressor with Soft Start fitted.

Electrical Connections

The diagram illustrates electrical connection terminals for a 400 V, 3 Ø, 50 Hz customer power supply. It lists terminal numbers and their corresponding functions, including remote emergency stop, fan speed inhibit, chiller run status and alarm status for System 1 and System 2, liquid pump contacts, remote start/stop, 1st and 2nd stage load limit or PWM input (depending on model), and EEV interface PCB connections. It also shows connections for a flow switch.

Space Requirements

The diagrams show recommended minimum clearances around the chiller units for adequate ventilation and service access. It is crucial to ensure sufficient space to prevent air discharged by the fans from recirculating into the condenser coil intake, which would reduce unit capacity. The dimensions at the front and rear of the units allow for access to the control panel and for component removal. The enclosure height should not exceed the height of the units, except that only one adjacent wall may be higher than the unit. Horizontal obstructions or overhangs should not be closer than 15 metres above the top of any unit, and no obstructions are allowed directly above the unit.

Dimensions

YCAL0147SB and 0173SB

Diagrams show the overall dimensions (Length, Width, Height) and center of gravity for models YCAL0147SB and 0173SB. Key dimensions include Length: 3022 mm, Width: 2045 mm, Height: 2282 mm. Center of Gravity from origin (mm) for YCAL0147SB: X=1491, Y=1022, Z=727. For YCAL0173SB: X=1503, Y=1022, Z=760. Features include rigging holes and water inlet/outlet connections.

YCAL0197SB, 0217SB and 0253SB

Diagrams show the overall dimensions (Length, Width, Height) and center of gravity for models YCAL0197SB, 0217SB, and 0253SB. Key dimensions include Length: 3022 mm, Width: 2311 mm, Height: 2473 mm. Center of Gravity from origin (mm) for YCAL0197SB: X=1430, Y=1167, Z=764. For YCAL0217SB: X=1430, Y=1159, Z=764. For YCAL0253SB: X=1437, Y=1159, Z=782. Features include rigging holes and water inlet/outlet connections.

YCAL0287SB and 0317SB

Diagrams show the overall dimensions (Length, Width, Height) and center of gravity for models YCAL0287SB and 0317SB. Key dimensions include Length: 3824 mm, Width: 2240 mm, Height: 2439 mm. Center of Gravity from origin (mm) for YCAL0287SB (Aluminum Fin Coils): X=1790, Y=1121, Z=1069. For YCAL0317SB (Aluminum Fin Coils): X=1790, Y=1121, Z=1069. Center of Gravity for Copper Fin Coils are slightly different for Z dimension. Features include rigging holes and water inlet/outlet connections.

YCAL0347SB and 0377SB

Diagrams show the overall dimensions (Length, Width, Height) and center of gravity for models YCAL0347SB and 0377SB. Key dimensions include Length: 4281 mm, Width: 2240 mm, Height: 2439 mm. Center of Gravity from origin (mm) for YCAL0347SB (Aluminum Fin Coils): X=2019, Y=1121, Z=1035. For YCAL0377SB (Aluminum Fin Coils): X=2019, Y=1121, Z=1035. Center of Gravity for Copper Fin Coils are slightly different for Z dimension. Features include rigging holes and water inlet/outlet connections.