User Manual

ManualsBrandsSiemens ManualsRefrigeration Valves (BC7)Valve insert ASR..N

716

Refrigerant Valves

PN 40

for industrial use in connection with

ammonia (R717) and other refrigerants

MVF661…N

•

One valve type for expansion, hot-gas and suction throttle applications

•

Hermetically sealed

•

Selectable standard interface DC 0/2...10 V or DC 0/4...20 mA

•

High resolution and control accuracy

•

Precise positioning control and position feedback signal

•

Short positioning time (< 1 second)

•

Closed when deenergized

•

Robust and maintenance-free

•

DN 25 with k

values from 0.16 to 6.3 m³/h

Use

The MVL661…N refrigerant valve is designed for modulating control of refrigerant

circuits including chillers and heat pumps. It is suitable for use in expansion, hot-gas

and suction throttle applications. In addition to ammonia (R717), the valve can handle

all standard refrigerants, noncorrosive gases / liquids and CO

(R744).

It is not suited for use with inflammable refrigerants.

CE2N4716en

08.06.2005

Building Technologies

HVAC Products

Summary of content (16 pages)

PAGE 1
4 Refrigerant Valves PN 40 716 MVF661…N for industrial use in connection with ammonia (R717) and other refrigerants • • • • • • • • • One valve type for expansion, hot-gas and suction throttle applications Hermetically sealed Selectable standard interface DC 0/2...10 V or DC 0/4...20 mA High resolution and control accuracy Precise positioning control and position feedback signal Short positioning time (< 1 second) Closed when deenergized Robust and maintenance-free DN 25 with kvs values from 0.
PAGE 2
Type summary The refrigeration capacity refers to applications using ammonia. Refrigerant valves Valve inserts Type reference DN kvs Q0 E Q0 H Q0 D [m /h] 3 [kW] [kW] [kW] MVF661.25-0.16N 25 0.16 95 10 2 MVF661.25-0.4N 25 0.40 245 26 5 MVF661.25-1.0N 25 1.0 610 64 12 MVF661.25-2.5N 25 2.5 1530 159 29 MVF661.25-6.3N 25 6.3 3850 402 74 Type reference DN kvs Q0 E Q0 H Q0 D [m /h] 3 [kW] [kW] [kW] ASR0.16N 25 0.16 95 10 2 ASR0.4N 25 0.
PAGE 3
Function / mechanical design Features and benefits • • • • • • 4 selectable standard signals for setpoint and measured value DIP switch to reduce the kvs value to 63 % of the nominal value Potentiometer for adjustment of minimum stroke for suction throttle applications Automatic stroke calibration Forced control input for “Valve closed” or “Valve fully open” LED for indicating the operating state The refrigerant valve can be driven by Siemens or third-party controllers that deliver a DC 0/2...
PAGE 4
Stroke kvs reduction 100 % 100 % k vs (switch 4 = off) Hmax 63 % k vs (switch 4 = on) Y-input 0% 0% Autocalibration 01124 100 % 4716D02en 63 % When kvs reduction (DIP switch 4 in position on) the stroke will be limited to 63 % mechanical stroke. 63 % of full stroke then corresponds to an input / output signal of 10 V. If, in addition, the stroke is limited to 80 %, for example, the minimum stroke will be 0.63 x 0.8 = 0.50 of full stroke.
PAGE 5
Engineering notes Depending on the application, it may be necessary to observe additional Installation Instructions and fit appropriate safety devices (e.g. pressurestats, full motor protection, etc.).
PAGE 6
Mounting notes The valve should be mounted and commissioned by qualified staff. The same applies to the replacement electronics and the configuration of the controller (e.g. SAPHIR or PolyCool).
PAGE 7
Functional valve data PN class Perm. pressure Max. differential pressure ∆pmax Leakage rate (internally across seat) Permissible media Materials Pipe connections Medium temperature External seal Valve characteristic (stroke, kv) Stroke resolution ∆H/H100 Mode of operation Position when deenergized Mounting position 2) Positioning time Valve body Seat / piston Sealing disk / O-rings Flanges Electrical connections Cable entry glands Min. cross-sectional area of cable Max.
PAGE 8
General environmental conditions Operation IEC 721-3-3 Class 3K6 –25...55 °C 10...100 % r. h. Climatic conditions Temperature Humidity Transport IEC 721-3-2 Class 2K3 –25...70 °C < 95 % r. h. Storage IEC 721-3-1 Class 1K3 –5...45 °C 5...95 % r. h. Connection terminals Transformer F MVF661...N G0 G0 System neutral G G System potential Y Y M M U OPEN CLOSED U ZC Operating voltage AC / DC 24 V DC 0 ... 10 V / 2 ... 10 V Control signal 0 ... 20 mA / 4 ... 20 mA Measuring neutral (= G0) DC 0 .
PAGE 9
Valve sizing with correction factor The applications and tables on the following pages are designed for help with selecting the valves.
PAGE 10
Step 1: Step 2: Step 3: Step 4: Step 5: Step 6: For tc = 35, calculate the value for to = –10 between values 20 and 40 in the table; result: 574 For tc = 35, calculate the value for to = 0 between values 20 and 40 in the table; result: 553 For to = –5, calculate the value for tc = 35 between correction factors 574 and 553; calculated in steps 1 and 2; result: 450 Calculate the theoretical kvs value; result: 0.46 m3/h Select the valve; the valve closest to the theoretical kvs value is the MVF661.25-0.
PAGE 11
Correction table KE Expansion valve R717 t c \ to -40 -30 -20 R22 -10 0 10 t c \ to -40 -30 -20 -10 0 00 324 265 124 00 82 68 37 20 481 488 494 481 376 124 20 101 104 107 105 81 18 40 581 590 598 605 612 618 40 108 111 114 118 120 123 60 662 673 683 693 701 708 60 104 108 112 116 119 122 t c \ to -40 -30 -20 -10 0 10 t c \ to -40 -30 -20 0 10 R744 R134a -20 226 149 00 262 264 241 166 20 245 247 247 246 213 -10 -1
PAGE 12
Use of the MVF661…N as a hot-gas valve The control valve throttles the capacity of a compressor stage. The hot gas passes directly to the evaporator, thus permitting capacity control in the range from 100 % down to approximately 0 %. + Indirect hot-gas bypass application 70179 Suitable for use in large refrigeration systems in air conditioning plant, to prevent unacceptable temperature fluctuations between the compressor stages. MVF661...
PAGE 13
Correction table KH Hot-gas valve R717 t c \ to -40 -30 -20 R22 -10 0 10 t c \ to -40 -30 -20 -10 0 00 20 19 14 00 8.9 8.4 6.3 20 38 38 38 38 35 19 20 15.3 15.1 14.,8 14.6 13.2 6.5 40 67 66 65 64 64 63 40 24.2 23.7 23.2 22.8 22.4 22.1 60 110 107 105 103 102 100 60 35.7 34.7 33.8 33.0 32.3 31.7 t c \ to -40 -30 -20 -10 0 10 t c \ to -40 -30 -20 0 10 R744 R134a -20 38.1 30.5 00 60.9 59.8 58.1 47.1 20 87.3 84.9 82.
PAGE 14
Use of the MVF661…N as a suction throttle valve + 70177 Typical control range 50...100 %. Minimum stroke limit control: To ensure optimum cooling of the compressor, MVF661...N either a capacity controller must be provided for – the compressor, or a minimum stroke must be set Bypass via the valve electronics. The minimum stroke can be limited to a maximum of 80 %. At zero load, the minimum stroke must be sufficient to ensure that the minimum gas velocity in the suction line is > 0.
PAGE 15
Correction table KS Suction throttle valve tc tc R717 R22 ∆pv100 \ to -40 -30 -20 -10 0 10 ∆pv100 \ to -40 -30 -20 -10 0 10 0.15 / 20 2.7 3.7 4.8 6.0 7.3 8.8 0.15 / 20 1.2 1.5 1.9 2.4 2.9 3.4 0.15 / 50 2.3 3.2 4.2 5.2 6.4 7.8 0.15 / 50 0.9 1.2 1.5 1.9 2.3 2.7 0.45 / 20 3.2 5.2 7.4 9.7 12.1 14.8 0.45 / 20 1.5 2.3 3.0 3.9 4.8 5.7 0.45 / 50 2.8 4.6 6.5 8.5 10.7 13.1 0.45 / 50 1.2 1.8 2.4 3.0 3.8 4.6 ∆pv100 \ to -40 -30 -20 -10 0 1
PAGE 16
/16 ©2005 Siemens Switzerland Ltd Building Technologies HVAC Products Refrigerant Valves PN 40 Subject to alteration CE2N4716en 08.06.