Danfoss MLM116 Application Manuallines Download Page 56

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Quadro unit MLZ/MLZ116

Operating principle

Composition of MLM/

MLZ116 quadro

MLM/MLZ116 quadro could only use active
system to balance the oil level between the
compressors. Each of the compressors may run
alone to provide proper capacity for part load

operation. The system has been designed to
ensure a precise pressure balancing between the
sumps, facilitating the oil equalization by gravity.

Active system

Active system (50 Hz)

1"5/8

1"3/8

1"1/8 (3x)

1"5/8

1"1/8

1"5/8

(3x)

2"5/8

Note: The dimensions are external diameters, for quadro systems, it is necessary to add support at discharge line. Active system

(50 Hz) excluding non-return valve, oil separator/reservoir and oil regulator. The compressors shown here are brazed version, but

could also work with rotolock version.

FRCC.PC.035.A4.02

Application Guidelines

Manifold compressors

Summary of Contents for MLM116

Page 1: ...Danfoss Scroll for Refrigeration MLM MLZ116 50Hz R404A R22 Application guidelines http cc danfoss com ...

Page 2: ......

Page 3: ...Content Single compressors 4 Manifold compressors 39 3 FRCC PC 035 A5 02 Application Guidelines ...

Page 4: ...temperature 19 Application envelope 19 Maximum discharge gas temperature 21 High and low pressure protection 22 On off cycling cycle rate limit 22 Defrost cycle 22 System design recommendations 23 General 23 Essential piping design considerations 23 Refrigerant charge limit 24 Off cycle migration 24 Liquid flood back 26 Specific application recommendations 27 Low ambient application 27 Scroll and ...

Page 5: ... Brazing material 32 Vacuum evacuation and moisture removal 33 Liquid line filter driers 33 Refrigerant charging 34 Insulation resistance and dielectric strength 34 Ordering information and packaging 35 Packaging 35 Packaging details 35 Industrial pack 35 Spare parts accessories 36 Content 5 FRCC PC 035 A5 02 Application Guidelines Single compressors ...

Page 6: ...ns and extends Danfoss refrigeration compressors to 26 8 kW 15 HP at common voltage and with a common refrigerant R404A R22 Thanks to its dedicated refrigeration design the MLZ MLM scroll compressor delivers a number of powerful advantages With its high efficiency motor and optimized scroll design it reduces energy cost in normal operating conditions and delivers high capacity and an optimized pre...

Page 7: ...pression pockets between the two scroll elements Low pressure suction gas is trapped within each crescent shaped pocket as it forms continuous motion of the orbiting scroll serves to seal the pocket which decreases in volume as the pocket moves towards the center of the scroll set with a corresponding increase in gas pressure Maximum compression is achieved as the pocket reaches the discharge port...

Page 8: ...ion T design optimized for refrigeration Motor protection B Electronic 230 V Tubing and electrical connections C brazed connections screw terminals Q rotolock connections screw terminals Motor voltage code 4 380 415 V 3 ph 50 Hz Other features Oil sight glass Oil equali zation Oil drain LP gauge port Gas equali zation port 5 Threaded Schrader Schrader None Threaded A 12345678 25 B Plant assembly l...

Page 9: ...Oil charge Net weight with oil COP EER W Btu h kW W W Btu h W cm3 rev m3 h Litres kg MLM116 15 24451 83427 10789 2 27 7 73 249 9 43 5 6 7 100 MLZ116 15 26865 91664 12127 2 22 7 56 249 9 43 5 6 7 100 Note EN12900 conditions To 10 C Tc 45 C RGT 20 C SC 0K 9 FRCC PC 035 A5 02 Application Guidelines Single compressors ...

Page 10: ... 8 181 279 4 60 90 90 30 Discharge 1 1 8 Ø 266 Ø 257 4 Suction 1 5 8 188 617 652 214 301 5 76 6 Ø 318 29 5 Without compression 28 0 With compression 531 1 2 345 279 4 183 157 4x Ø 19 43 30 428 212 90 371 304 8 60 181 Black Blue Brown Faston 1 4 tabs Power supply Sump heater Module power supply M1 M2 control circuit HM 8 bolt Lock washer Flat washer Steel mounting sleeve Rubber grommet Nut 28 mm Co...

Page 11: ...onnection Oil sight glass Danfoss MLZ MLM116 scroll compressors come equipped with a sight glass 1 1 8 18 UNF which may be used to determine the amount and condition of the oil contained within the sump The oil fill connection and gauge port is a 1 4 male flare connector incorporating a Schrader valve MLM MLZ116 2 1 4 Rotolock connector allowing the use of 2 1 4 1 3 8 This connection must be used ...

Page 12: ...minal on the power leads Wiring connections Motor voltage code 4 Nominal voltage 50 Hz 380 415 3ph Voltage range 50 Hz 340 457 V The terminal box is provided with 2 triple knockouts and 1 single knockout for power supply and 4 double knockouts for the safety control circuit The 3 power supply knockouts accommodate the following diameters Ø 50 8 mm UL 1 1 2 conduit and Ø 43 7 mm UL 1 1 4 conduit an...

Page 13: ...nerally low and it requires adapted tools for precise measurement Use a digital ohm meter a 4 wires method and measure under stabilized ambient temperature Winding resistance varies strongly with winding temperature If the compressor is stabilized at a different value than 25 C the measured resistance must be corrected using following formula a tamb Rtamb R25 C _______ a t25 C t25 C reference temp...

Page 14: ...safety switch trips the compressor must stop immediately and must not re start until the tripping condition is back to normal and the safety switch is closed again This applies to the LP safety switch the HP safety switch the discharge gas thermostat and the motor safety thermostat In specific situations such as winter start operation an eventual LP control for pump down cycles may be temporarily ...

Page 15: ...evice provides for efficient and reliable protection against overheating overloading phase loss reversal The motor protector comprises a control module and PTC sensors embedded in the motor winding The close contact between thermistors and windings ensures a very low level of thermal inertia The motor temperature is being constantly measured by a PTC thermistor loop connected on S1 S2 If any therm...

Page 16: ...s are active during a 5 sec window 1 second after compressor start up power on L1 L2 L3 Compressor start Phase monitoring 0 1 s 6 s Phase sequence module logic Should one of these parameters be incorrect the relay would lock out contact M1 M2 open The red led on the module will show the following blink code In case of phase reverse error Appr 1 second In case of phase loss error Appr 1 second Vavg...

Page 17: ...fications Internal free volume Products Internal free volume at LP side without oil liter Internal free volume at LP side with oil liter MLM MLZ116 28 8 22 1 17 FRCC PC 035 A5 02 Application Guidelines Single compressors ...

Page 18: ...ther parameters that can influence the discharge temperature R404A PVE R404A is an HFC refrigerant R404A has zero ozone depletion potential ODP 0 R404A is especially suitable for low evaporating temperature applications but it can also be applied to medium evaporating temperature applications R404A is a mixture and has a very small temperature glide and therefore must be charged in its liquid phas...

Page 19: ...erheat Minimum and maximum evaporating and condensing temperatures as per the operating envelopes MLZ MLM compressors can be applied from 35 C to 55 C ambient temperature The compressors are designed as 100 suction gas cooled without need for additional fan cooling Ambient temperature has very little effect on the compressor performance In case of enclosed fitting and high ambient temperature it s...

Page 20: ...GT 20 C Superheat 10 K MLM 116 R22 10 15 20 25 30 35 40 45 50 55 60 65 70 75 35 30 25 20 15 10 5 0 5 10 15 20 Evaporating temperature C Condensing temperature C 20 FRCC PC 035 A5 02 Application Guidelines Single compressors ...

Page 21: ...ed thermocouple or thermostat attached to the discharge line 15 cm 6 inches from the compressor shell Maximum discharge gas temperature must not exceed 135 C 275 F when the compressor is running within the approved operating envelope Maximum discharge gas temperature MLZ116 RGT 20 C Example 2 Example 1 Superheat 10 K Condensing temperature C Evaporating temperature C 35 30 25 20 15 10 5 0 5 10 15 ...

Page 22: ...ow pressure safety switch setting bar g 0 5 0 7 Recommended pump down switch settings 1 5 bar below nominal evaporating pressure Minimum low pressure pump down switch setting bar g 0 6 0 9 LP safety switch shall never have time delay For MLZ MLZ116 a high pressure switch is required to shut down the compressor should the discharge pressure exceed the values shown in the table above The high pressu...

Page 23: ... manufacturers should specify precautions for any applications that exceed these limits to ensure compressor reliability Piping should be designed with adequate three dimensional flexibility figure 2 It should not be in contact with the surrounding structure unless a proper tubing mount has been installed This protection proves necessary to avoid excess vibration which can ultimately result in con...

Page 24: ...ent temperature Raise the ambient temperature to 20 C and maintain it for 10 minutes Start the compressor and monitor sump temperature sight glass indication and sound level The presence of liquid in the crankcase can be easily detected by checking the sump level through the oil sight glass Foam in the oil sump indicates a flooded start A noisy start oil loss from the sump and sump cool down are i...

Page 25: ...switch resets should be limited to avoid short cycling of the compressor Use dedicated wiring and an additional relay which allows for one shot pump down The pump down allows stroage of all the refrigerant in the high pressure side circuit On unitary or close coupled systems where the system refrigerant charge is expected to be both correct and definable the entire system charge Liquid line soleno...

Page 26: ...the refrigerant entering the compressor is still in liquid state A continuous liquid flood back will cause oil dilution and in extreme situations lead to lack of lubrication and high rate of oil leaving the compressor Liquid flood back test Repetitive liquid flood back testing must be carried out under TXV threshold operating conditions a high pressure ratio and minimum evaporator load along with ...

Page 27: ... ensure satisfactory condensing and suction pressures the use of a head pressure control valve is recommended Note This solution requires extra refrigerant charge which can introduce other problems A non return valve in the discharge line is recommended and special care should be taken when designing the discharge line For further information please contact Danfoss Low ambient start up Under cold ...

Page 28: ...razed plate condenser heat exchanger a sufficient free volume for the discharge gas to accumulate is required in order to avoid excess pressure build up At least 1 meter of discharge line is necessary to generate this volume To help reduce the discharge gas volume immediately after start up the supply of cooling water to the heat exchanger may be opened before the compressor starts to remove super...

Page 29: ...d to be quiet and the frequency of the sound generated is pushed into the higher ranges which not only are easier to reduce but also do not generate the penetrating power of lower frequency sound Use of sound insulation materials on the inside of unit panels is an effective means of substantially reducing the sound being transmitted to the outside Ensure that no components capable of transmitting ...

Page 30: ... transmitted to the frame The tubing should be designed so as to both reduce the transmission of vibrations to other structures and withstand vibration without incurring any damage Tubing should also be designed for three dimensional flexibility For more information on piping design please see the section entitled Essential piping design considerations Gas pulsation The MLZ MLM scroll compressors ...

Page 31: ...se both these rings when lifting the compressor Use lifting equipment rated and certified for the weight of the compressor A spreader bar rated for the weight of the compressor is highly recommended to ensure a better load distribution The use of lifting hooks closed with a clasp and certified to lift the weight of the compressor is also highly recommended Always respect the appropriate rules conc...

Page 32: ...l wiring is connected to the compressor Protect the terminal box and compressor painted surfaces from torch heat damage see diagram Use only clean refrigeration grade copper tubing and clean all connections Purge nitrogen through the compressor in order to prevent against oxidation and flammable conditions The compressor should not be exposed to the open air for extended periods Use of a double ti...

Page 33: ...ompressors R404A with PVE oil For servicing of existing installations where acid formation may be present the Danfoss DCL solid core filter drier containing activated alumina is recommended After burn out remove replace the liquid line filter drier and install a Danfoss type DAS burnout drier of the appropriate capacity Refer to the DAS drier instructions and technical information for correct use ...

Page 34: ...tion resistance Danfoss recommends that the system be first operated briefly to distribute refrigerant throughout the system Following this brief operation retest the compressor for insulation resistance or current leakage Never reset a breaker or replace a fuse without first checking for a ground fault a short circuit to ground Be alert for sounds of arcing inside the compressor In installations ...

Page 35: ...s Compressors MLZ116 MLM116 Pack type Industrial pack Compressors per pallet 6 Static stacking of pallets 2 Shipped accessories 4 bolts per compressor Included 4 washers per compressor Included 4 grommets per compressor Included 4 extra sleeves per compressor Included Additional accessories for rotolock version 2 gasket Included Industrial pack Compressors Model variation Connections Features Volt...

Page 36: ...Packaging Pack size G07 8156132 Gasket 1 3 4 Models with 1 3 4 rotolock connection Multipack 10 G07 7956003 Gasket 1 3 4 Models with 1 3 4 rotolock connection Industry pack 50 G08 8156133 Gasket 2 1 4 Models with 2 1 4 rotolock connection Multipack 10 G08 7956004 Gasket 2 1 4 Models with 2 1 4 rotolock connection Industry pack 50 Solder sleeve Type Code n Description Application Packaging Pack siz...

Page 37: ...Application Packaging Pack size MCI 50 CM 7705009 Electronic soft start kit MCI 50 C MLM MLZ116 Single pack 1 Motor protection modules Type Code n Description Application Packaging Pack size 120Z0585 Electronic motor protection module 110 240 V MLM MLZ116 Single pack 1 Surface sump heaters Code no Accessory description Application Packaging Pack size 120Z0377 56W 400V surface sump heater bottom in...

Page 38: ...k 10 120Z0458 Terminal box 210 x 190 mm incl cover MLM MLZ116 Single pack 1 120Z0462 Terminal box 210 x 190 incl cover and module wiring for 258 x 208 and 186 x 198 terminal box replacement MLM MLZ116 Single pack 1 except code 3 Lubricant Miscellaneous Type Code No Description Application Packaging Pack Size 160P 7754001 Mineral oil 160P 2 litre can MLM116 Multipack 8 160P 7754002 Mineral oil 160P...

Page 39: ... accumulator 47 Suction header 47 Oil level regulator 48 Oil separator oil reservoir 48 Oil separator for active system 49 Installation and service 50 Piping design 50 Wiring and rotation direction 50 Failure analysis 50 Ordering information 51 Tandem unit MLM MLZ116 52 Operating principle 52 Composition of MLM MLZ116 tandem 52 Compressor mounting 53 Oil equalisation connection 53 Trio unit MLM ML...

Page 40: ...n line and common discharge line The technique of mounting compressors in parallel is also referred to as manifolding In a system with only two compressors this is referred to as a tandem configuration The main reason for manifolding is reduced operating cost through greater control of capacity and power consumption This is achieved by staggering the compressor switch on sequences that allow the p...

Page 41: ...the oil level regulator and the oil separator which can supply the oil when required The active system can thus accommodate itself to various oil conditions Danfoss has qualified tandem trio quadro composition for active systems Each compressor will equip the oil level regulator to facilitate the oil level balance To avoid refrigerant back flow from high pressure it is always recommended to have a...

Page 42: ...lve Oil filter A passive system is an oil management system without any measurement or control devices such as oil level regulators and oil controllers By contrast a solution equipped with such measurement or control devices is called an active system Danfoss has qualified only the even tandem two same compressors for passive solutions 42 FRCC PC 035 A4 02 Application Guidelines Manifold compresso...

Page 43: ... avoid refrigerant back flow from high pressure it is always recommended to have a non return valve on the discharge line of each compressor as well as one non return valve on the outlet of the oil separator in the system to prevent refrigerant migration The following are recommendations from Danfoss application engineering using an oil equalization line system without active control An adequately...

Page 44: ...essors are also allowed for parallel assemblies For more details please refer to the MLM MLZ116 application guidelines The pump down pressure switch must have a set point slightly higher than the lowest compressor safety pressure switch set point The compressor switch must never be bypassed and shall stop all the compressors The high pressure safety pressure switch shall stop all the compressors W...

Page 45: ...ost hot gas bypass defrost reversible defrost etc For the system which use hot gas bypass or reversible defrost method suction accumulator is necessary as a result of the possibility of a substantial quantity of liquid refrigerant remaining in the evaporator this liquid refrigerant can then return to the compressor either flooding the sump or as a dynamic liquid slug when the cycle switch back to ...

Page 46: ... evaporator is situated below the compressor the suction riser must be trapped to ensure the oil return to the compressor see fig 1 When the condenser is mounted at a higher position than the compressor a suitably sized U shaped trap close to the compressor is necessary to prevent oil leaving the compressor from draining back to the discharge side of the compressor during off cycle The upper loop ...

Page 47: ...pplication suction accumulator is a must unless approved by careful tests under different operating conditions If the system use hot gas bypass or reversible defrost method suction accumulator is necessary Selection of a suction line accumulator should be made on the basis of the following three capabilities 1 The accumulator should have an adequate liquid holding capacity that can vary with the s...

Page 48: ...turning refrigerant gas and oil to each individual compressor also the suction header should be installed horizontally The gas velocity in the suction header must be a maximum of 4 m s The suction line and the suction header must be insulated to limit suction gas superheat Passive system Oil separator oil reservoir Oil separator for passive system The role of the oil separator is to intercept the ...

Page 49: ...n active solutions These systems store the oil in a common oil separator reservoir at compressor discharge pressure see the figure below The advantage is that these systems do not need a separated oil reservoir but make use of a combined oil separator reservoir arrangement which normally results in a cost saving over traditional low pressure systems additional oil separator and oil reservoir insta...

Page 50: ...d must be horizontal so as not to trap oil Please contact Danfoss Sales for specific drawings All compressors in a manifolding unit must be electrically wired individually Compressors should run with the correct rotation direction This can be achieved by having the correct phase sequence on each compressor motor terminal L1 T1 L2 T2 L3 T3 When one compressor in a parallel system fails the chance o...

Page 51: ...ystem 7777041 1 7777045 2 Even tandem with active system 7777045 2 Even trio with active system 7777049 1 7777045 3 Even quadro with active system 7777041 2 7777045 4 Kit code number 7777041 Kit code number 7777049 Designation Qty Grommet Sleeves M 6 Flat Washers LL10Z 6 Washers 6 Washer for tandem quadro 6 Grommets 6 Sleeve 2 1 4 Rotolock 1 3 8 ODF 2 Teflon seal Φ 50 8 mm 2 Designation Qty Gromme...

Page 52: ...he system has been designed to ensure a precise pressure balancing between the sumps facilitating the oil equalization by gravity Active system Active system 50 Hz 1 1 8 1 5 8 1 5 8 1 5 8 2 1 8 Note The dimensions are external diameters Active system 50 Hz excluding non return valve oil separator reservoir and oil regulator The compressors shown here are brazed version but could also work with rot...

Page 53: ...sing grommet sleeves flat washers washers and and the grommets provided in kit 7777041 HM10 x 100 Ø 25 Ø 10 Supplied with the kit 7777045 Included in kit 7777041 Not supplied The level of oil naturally balances by a pipe of 1 3 8 To fix this oil connection equalization Rotolock the adaptor sleeves 2 1 4 1 3 8 and Teflon seals included in kit 7777041 must be used Oil equalization connection Tighten...

Page 54: ...en designed to ensure a precise pressure balancing between the sumps facilitating the oil equalization by gravity Active system Active system 50 Hz 1 1 8 2x 1 5 8 1 5 8 3x 2 5 8 1 1 8 1 3 8 Note The dimensions are external diameters Active system 50 Hz excluding non return valve oil separator reservoir and oil regulator The compressors shown here are brazed version but could also work with rotoloc...

Page 55: ...y using grommet sleeves flat washers washers and and grommets provided in kit 7777040 Compressor mounting HM10 x 100 Ø 25 Ø 10 Supplied with kit 7777045 Included in kit 7777049 Not supplied 55 FRCC PC 035 A4 02 Application Guidelines Manifold compressors ...

Page 56: ...essure balancing between the sumps facilitating the oil equalization by gravity Active system Active system 50 Hz 1 5 8 1 3 8 1 1 8 3x 1 5 8 1 1 8 1 5 8 3x 2 5 8 Note The dimensions are external diameters for quadro systems it is necessary to add support at discharge line Active system 50 Hz excluding non return valve oil separator reservoir and oil regulator The compressors shown here are brazed ...

Page 57: ...y using grommet sleeves flat washers washers and and the grommets provided in kit 7777041 Compressor mounting HM10 x 100 Ø 25 Ø 10 Supplied with kit 7777045 Included in kit 7777041 Not supplied 57 FRCC PC 035 A4 02 Application Guidelines Manifold compressors ...

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Page 60: ...oned us as distinct variable speed technology specialists Today we operate from engineering and manufacturing facilities spanning across three continents FRCC PC 035 A5 02 Danfoss DCS CC 2017 07 Our products can be found in a variety of applications such as rooftops chillers residential air conditioners heatpumps coldrooms supermarkets milk tank cooling and industrial cooling processes http cc dan...

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