Siemens Industry, Inc. MVS661..N… Series Technical Instructions Document No. 155-404 May 11, 2016 Modulating Refrigerant Valves for Ammonia (R717) and Safety Refrigerants Description Modulating refrigerant valves designed for modulating control of refrigerant circuits including chillers and heat pumps. Features One valve type for expansion, hot-gas and suction throttle applications. Hermetically sealed. Selectable standard control signals 0/2 to 10 Vdc or 0/4 to 20 mA. High resolution and control accuracy. Precise positioning control and position feedback signal. Short positioning time (less than 1 second). Closed when de-energized. Robust and maintenance-free. 1-inch (DN 25) with CV (k vs ) values from 0.12 to 7.28 (0.10 to 6.3 m³/h). Application The MVS661..N refrigerant valves are suitable for use in expansion, hot-gas and suction throttle applications. In addition to ammonia (R717), the valves can handle all standard safety refrigerants, non-corrosive gases/liquids and CO 2 (R744). They are not suitable for flammable refrigerants. Product Numbers See Product Summary. Warning/Caution Notations WARNING: Personal injury or loss of life may occur if you do not follow the procedures as specified. CAUTION: Equipment damage or loss of data may occur if you do not follow the procedures as specified. Technical Instructions MVS661..N Series Modulating Refrigerant Valves Document Number 155-404 for Ammonia (R717) and Safety Refrigerants May 11, 2016 Page 2 Siemens Industry, Inc. Product Numbers The refrigeration capacity refers to applications using ammonia. Table 1. Product Numbers. Product Number Line Size In (mm) C V (k vs ) C V (k vs ) Reduced p max psi [MPa] Q 0 E [kW] Q 0 H [kW] Q 0 D [kW] S NA [VA] P med [W] MVS661.25-016N 1 (25) 0.18 (0,16) 0.12 (0,10) 363 (2,5) 95 10 2 22 12 MVS661.25-0.4N 0.46 (0,40) 0.29 (0,25) 245 26 5 MVS661.25-1.0N 1.16 (1,0) 0.73 (0,63) 610 64 12 MVS661.25-2.5N 2.89 (2,5) 1.85 (1,6) 1530 159 29 MVS661.25-6.3N 7.28 (6,3) 4.62 (4,0) 3850 402 74 Cv = Nominal flow rate of refrigerant through the fully open valve (H 100 ) at a differential pressure of 1 psi. k vs = Nominal flow rate of refrigerant through the fully open valve (H 100 ) at a differential pressure of 100 kPa (1 bar) to VDI 2173. If required k vs -value and refrigeration capacity Q 0 can be reduced to 63% (see C V (k vs ) reduction). ∆p max = Maximum permissible differential pressure across the control path of the valve, valid for the entire actuating range of the motorized valve. Q 0 E = Refrigeration capacity in expansion applications. Q 0 H = Refrigeration capacity in hot-gas bypass applications. Q 0 D = Refrigeration capacity in suction throttle applications and ∆p = 7.25 psi (0.5 bar). S NA = Nominal apparent power for selecting the transformer. P med = Typical power consumption The pressure drop across evaporator and condenser is assumed to be 4.35 psi (0.3 bar) each, and 23 psi (1.6 bar) upstream of the evaporator (for example, spider). The capacities specified are based on superheating by 6K and sub-cooling by 2K. Accessories Valve insert ASR..N Table 2. Accessories. Product Number Line Size In (mm) C V (k vs ) ASR0.16N 1 (25) 0.18 (0,16) ASR0.4N 0.46 (0,40) ASR1.0N 1.16 (1,0) ASR2.5N 2.89 (2,5) ASR6.3N 7.28 (6,3) The refrigeration capacity for various refrigerants and operating conditions can be calculated for the three types of application using Table 6 through Table 11. For accurate valve sizing, use the valve selection program Refrigeration VASP. Ordering The valve body and magnetic actuator form one integral unit and cannot be separated. MVS661…N Modulating Refrigerant Valves Technical Instructions for Ammonia (R717) and Safety Refrigerants Document Number 155-404 May 11, 2016 Siemens Industry, Inc. Page 3 Operator controls and indicators in the electronics housing 1 Connection terminals 2 LED for indication of operating state 3 Minimal stroke setting potentiometer Rv 4 Auto-calibration 5 DIP switches for mode control Replacement Parts If the valve’s electronics become faulty, the entire electronics housing must be replaced by spare part ASR61, which is supplied with Mounting Instructions (74 319 0270 0). If the installation is resized, or if excessive wear impacts the valve’s performance, a new valve insert (ASR…N) will restore the valve’s characteristics to its original specifications. The valve insert is supplied complete with Mounting Instructions (74 319 0486 0). Technical Design/ Functions Features and Benefits Four selectable control signals for setpoint and measured value. DIP switch to reduce the C V (k vs ) 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. Control The MVS661… Series refrigerant valve can be driven by Siemens or third-party controllers that deliver a 0/2 to10 Vdc, or 0/4 to 20 mA output signal. For optimum control performance, use a 4-wire connection between the controller and valve. The valve stroke is proportional to the control signal. The valve stroke is proportional to the control signal. CAUTION: You must use a four-wire connection with Vdc power supply. Spring return action If the control signal is interrupted, or in the event of a power failure, the valve’s return spring will automatically close control path. Technical Instructions MVS661..N Series Modulating Refrigerant Valves Document Number 155-404 for Ammonia (R717) and Safety Refrigerants May 11, 2016 Page 4 Siemens Industry, Inc. DIP Switch Configurations Table 3. DIP Switch Configurations. Switch Function ON/OFF Description Positioning signal Y ON Current (mA) OFF Voltage (V) 1) Positioning range Y and U ON 2 to 10 Vdc, 4 to 20 mA OFF 0 to 10 Vdc, 0 to 20 mA 1) Position feedback U ON Current (mA) OFF Voltage (V) 1) Nominal flow rate C V (k vs ) ON 63% OFF 100% 1) 1) Factory setting C V (K VS ) reduction For C V (k vs ) reduction (DIP switch 4 in position ON), the stroke is limited to 63% mechanical stroke. 63% of full stroke then corresponds to an input/output signal of 10V. If, in addition, the stroke is limited to 80%, for example, the minimum stroke is 0.63 × 0.8 = 0.50 of full stroke. Minimum stroke setting With a suction throttle valve, it is essential that a minimum stroke limit be maintained to ensure compressor cooling and efficient oil return. This can be achieved with a re-injection valve, a bypass line across the valve, or a guaranteed minimum opening of the valve. The minimum stroke can be defined using the controller and control signal Y, or it can be set directly with potentiometer Rv. The factory setting is zero (mechanical stop in counterclockwise direction, CCW). The minimum stroke can be set by turning the potentiometer clockwise (CW) to a maximum of 80% C V (k vs ). CAUTION: Do not use potentiometer Rv to limit the stroke on expansion applications. The valve must be able to fully close. MVS661…N Modulating Refrigerant Valves Technical Instructions for Ammonia (R717) and Safety Refrigerants Document Number 155-404 May 11, 2016 Siemens Industry, Inc. Page 5 Forced control input ZC Signal priority 1. Forced control signal ZC. 2. Signal input Y and/or minimum stroke setting with potentiometer Rv possible. Calibration The printed circuit board of the MVS661… Series has a slot to facilitate calibration. To calibrate, insert a screwdriver in the slot so that the contacts inside are connected. As a result, the valve will first be fully closed and then fully opened. Calibration matches the electronics to the valve mechanism. During calibration, the green LED flashes for about 10 seconds; see Table 4. Figure 1. Calibration Slot. NOTE: MVS661..-.. Refrigerant Valves are supplied fully calibrated. When is calibration required? Calibrate after replacing the electronics, when the red LED is lit or flashing, or when the valve is leaking (at seat). Technical Instructions MVS661..N Series Modulating Refrigerant Valves Document Number 155-404 for Ammonia (R717) and Safety Refrigerants May 11, 2016 Page 6 Siemens Industry, Inc. Table 4. Indication of Operating State. LED Indication Operating State, Function Remarks, Troubleshooting Green Lit Control mode Automatic operation; everything is OK. Flashing Calibration in progress Wait until calibration is finished (green or red LED will be lit). Red Lit Calibration error Internal error Recalibrate (operate button in opening 1×). Replace electronics module. Flashing Main fault Check electric main network (outside the frequency or voltage range). Both Dark No power supply Electronics faulty Check electric main network, check wiring Replace electronics module. Connection type 4-wire connection 3-wire connection NOTE: Four-wire connections are always preferred. Product Number (VA) (W) (A) Wire Gauge (AWG) 14 12 10 Max. Cable Length Ft (m) MVS661..-.. 22 12 1.6 to 4A 213 (65) 361 (110) 525 (160) MVS661..-.. 22 12 1.6 to 4A 65 (20) 115 (35) 164 (50) S NA = Nominal apparent power for selecting the transformer. P med = Typical power consumption. I F = Required slow fuse. L = Maximum cable length; with 4-wire connections, the maximum permissible length of the separate 14 AWG (1.5 mm 2 ) copper positioning signal wire is 656 ft (200 m). 1) All information at 24 Vac. 2) With 10 AWG (4 mm 2 ) electrical wiring reduce wiring cross-section for connection inside valve to 12 AWG (2.5 mm 2 ). Sizing For straightforward valve sizing, see Application Examples, beginning on page 12 for the relevant application. For accurate valve sizing, Siemens Industry, Inc. recommends using the valve sizing software Refrigeration VASP. NOTE: The refrigeration capacity Q 0 is calculated by multiplying the mass flow by the specific enthalpy differential found in the h, log p-chart for the relevant refrigerant. To easily determine the refrigeration capacity, see the selection chart provided for each application. With direct or indirect hot-gas bypass applications, the enthalpy differential of Q c (the condenser capacity) must also be taken into account when calculating the refrigeration capacity. If the evaporating and/or condensing temperatures are between the values shown in the tables, the refrigeration capacity can be determined with reasonable accuracy by linear interpolation. See Application Examples. At the operating conditions given in the tables, the permissible differential pressure p max 363 psi (25 bar) across the valve is within the admissible range for these valves. If the evaporating temperature is raised by 1K, the refrigeration capacity increases by about 3%. If sub-cooling is increased by 1K, the refrigeration capacity increases by about 1 to 2% (this applies only to sub-cooling down to approximately 8K). MVS661…N Modulating Refrigerant Valves Technical Instructions for Ammonia (R717) and Safety Refrigerants Document Number 155-404 May 11, 2016 Siemens Industry, Inc. Page 7 Engineering Notes Depending on the application, additional installation instructions may need to be observed and appropriate safety devices (such as pressostats, full motor protection, and so on) fitted. WARNING: To prevent damage to the seal inside the valve insert, the plant must be vented on the low-pressure side following a pressure test (valve outlet port), or the valve must be fully open during the pressure test and during venting (power supply connected and positioning signal at maximum or forced opening by G ZC). Expansion application To prevent formation of flash gas on expansion applications, the velocity of the refrigerant in the fluid pipe may not exceed 3.3 ft/s (1 m/s). To assure this, the diameter of the fluid pipe must be greater than the nominal size of the valve. 1 = Evaporator 2 = Compressor 3 = Condenser 4 = Expansion valves a) The differential pressure over reduction must be less than half the differential pressure Δp FL . b) The inlet path between diameter reduction and expansion valve inlet: Must be straight for at least 2 feet (600 mm). Must not contain any valves. WARNING: A filter/dryer must be mounted upstream of the expansion valve. The valve is not explosion-proof. Installation Notes The valve should be mounted and commissioned by a qualified installer. The same applies to the replacement electronics and the configuration of the controller. The refrigerant valves can be mounted in any orientation above horizontal, but upright mounting is preferable. Arrange the pipework so that the valve is not located at a low point in the plant where oil can collect. Fit the pipes so that the alignment does not distort the valve connections. Fix the valve body so that that it cannot vibrate. Vibration can cause connection pipes to burst. Before soldering the pipes, ensure that the direction of flow through the valve is correct. Carefully solder the pipes. To avoid dirt and the formation of scale (oxide), inert gas is recommended for soldering. Technical Instructions MVS661..N Series Modulating Refrigerant Valves Document Number 155-404 for Ammonia (R717) and Safety Refrigerants May 11, 2016 Page 8 Siemens Industry, Inc. Installation Notes, Continued The flame should be large enough to ensure that the junction heats up quickly and the valve does not get too hot. The flame should be directed away from the valve. During soldering, cool the valve with a wet cloth, for example, to ensure that it does not become too hot. The valve is supplied complete with mounting instructions (Document Number 74 319 0232 0). Maintenance The refrigerant valve is maintenance-free. Repair The electronics can be replaced by ordering the ASR61 Service Kit. If the valve’s interior is subjected to extensive wear, the valve can be repaired by replacing the ASR.N valve insert. Warranty Observe all application-specific technical data. NOTE: If you ignore specified limits, Siemens Industry, Inc. will not assume any responsibility. Specifications Electrical Power supply (extra low-voltage use only) (SELV, PELV) 24 Vac Operating voltage 24 Vac ± 20% Frequency 45 to 65 Hz Typical power consumption P med 12W Standby <1 W (valve fully closed) Rated apparent power, S NA 22 VA (for selecting the transformer) Required fuse Slow, 1.6 to 4A 24 Vdc Operating voltage 20 to 30 Vdc Current draw 0.5A/2A (maximum) Signal inputs Control signal Y 0/2 to 10 Vdc, 0/4 to 20 mA Impedance 0/2 to 10 Vdc 100K ohm/5nF (load <0.1 mA) 0/4 to 20 mA 240 ohm/5nF Forced control ZC Input impedance 22K ohm Closing the valve (ZC connected to G0) <1 Vac; <0.8 Vdc Opening the valve (ZC connected to G) >6 Vac; >5 Vdc No function (ZC not wired) Positioning signal Y active Signal outputs Position feedback signal U Voltage 0/2 to 10 Vdc; load resistance > 500 Ω Current 0/4 to 20 mA; load resistance < 500Ω Stroke measurement Inductive Non-linearity Accuracy +3% full scale Positioning time Less than 1 second Electrical connections Connection terminals Screw terminals for 12 AWG wire MVS661…N Modulating Refrigerant Valves Technical Instructions for Ammonia (R717) and Safety Refrigerants Document Number 155-404 May 11, 2016 Siemens Industry, Inc. Page 9 Functional valve data Permissible Operating pressure 1) max. 914 psi (63 bar) Maximum differential pressure p max 363 psi (25 bar) Valve characteristic Linear Leakage rate (internally across seat) Max. 0.002% C V (K Vs ) resp. Max. 1 NI/h gas at p = 58 psi (4 bar) Shut/off function, like solenoid normally closed (NC) function External seal Hermetically sealed Permissible media Ammonia (R717), CO2 (R744) and all safety refrigerants (R22, R134a, R404A, R407C, R507, and so on). Not suited for use with inflammable refrigerants Media temperature -40°F to 248°F (-40°C to 120°C), Max. 284°F (140°C) for 10 min. Stroke resolution H/H 100 1:1000 (H = Stroke) Hysteresis Typically 3% Mode of operation Modulating Position when de-energized Closed Orientation 2) Upright to horizontal Materials Valve body and parts Steel/CrNi steel Seat/piston CrNi steel Sealing disk/O-rings PTFE/CR (chloroprene) Pipe connections Solder (weld-on-ends) Referring to EN 1092-1 and ASME B16.25 schedule 40 Inner diameter 0.88 in (22.4 mm) Outer diameter 1.33 in (33.7 mm) Ambient conditions Temperature-13°F to 131°F (-25°C to 55°C) Humidity 10 to 100% rh Miscellaneous Weight 11.40 lb (5.17 kg) Dimensions See Error! Reference source not found. Agency approvals Degree of protection IP65 as per EN 60529 2) Conforms to CE requirements UL Certified to UL 873 cUL Certified to CSA C22.2 No. 24 Conforms to RCM requirements Electrical safety EN 60730-1 Protection class Class III as per EN 60730 Pollution degree Degree 2 as per EN 60730 Vibration 3 EN 60068-2-6 5g acceleration, 10 to 150 Hz, 2.5 h (5g horizontal, max. 2g upright) Next >