Electrical Control Valves

Transcription

1 172 Electrical Control Valves

2 Electrical Control Valves Electrical Control Valve Technology Thermostatic expansion valves and mechanical regulator valves have been used in the refrigeration and air conditioning industry to control superheat and refrigerant mass flow since its very beginning. As today s systems require improved energy efficiency, tighter control, a wider range of operating conditions and incorporate new features like remote monitoring and diagnostics, the application of electronically operated valves becomes mandatory. Only these offer the controls performance necessary to meet these needs. Electrical control valves are actuators only. For operation in a system they need sensors, valve drivers and controllers, see next chapter. The EXM/EXL biflow valves for OEM use are equipped with an unipolar stepper motor drive. They are mainly used for heat pumps, air conditioning and close control. The EX2 is designed for pulse width modulation. It is applicable to all common HCFC and HFC refrigerants and for subcritical CO 2 applications and is used mainly for refrigeration applications such as display cases. The EX2 valve is a slide type solenoid valve with an orifice for expansion. It is either completely open or completely closed. One common valve body can be combined with 6 interchangeable orifices to cover 7 capacity ranges. The CX2 features the same technology and advantages as the EX2, however it is applicable to high-pressure CO 2 applications. The EX4/EX5/EX6/EX7/EX8 consist of two main internal assemblies, the valve and the stepper motor. The stepper motor is located next to the electrical plug and connected directly to the slide and cage assembly of the valve. Similar to the technology used in compressors, the motor is exposed to refrigerant and lubricant and the materials used are identical to the ones in compressor motors. The housing of the motor and valve assembly is made from stainless steel and fully hermetic, utilising exclusively brazing and welding technologies and eliminating all gaskets. This design offers several technical advantages such as proportional linear mass flow and a wide capacity range. A common feature of all EX2, EX4-8 electrical control valves is the positive shut-off function, which eliminates the need for additional solenoid valves. The CX4/CX5/CX6/CX7 High Pressure Expansion Valves are stepper motor driven valves for precise control of R744 (CO 2 ) refrigerant mass flow in air conditioning, refrigeration and heat pump applications. The Control Valves also can be used for liquid injection duty and hot gas bypass. Valve Selection For the EX2, the published table quotes capacities at 100% duty cycle, i.e. valve open continuously. However, it is recommended to operate the valve at partial load (50-80%) to allow for system load fluctuations. For EX4/EX5/EX6/EX7/EX8 and EXM/EXL valves, all published capacities are maximum and there are no reserve capacities. Each valve should be selected for the highest possible capacity of the system. A wide range regulation (10 100%) with one slide orifice for each valve is achievable. To facilitate valve dimensioning for other than the standard conditions, Emerson Climate offers the program Controls Navigator. This can be downloaded from Selection Table for Electrical Control Valves and Applicable Controllers Valve type EXM EXL Function Capacity kw Expansion Valve Feature Main Application Applicable Controller Uni polar stepper motor driven Heat pumps, Air Conditioning, Close Control EXD-HP1/2 Superheat Controller (Modbus) EX2 Expansion Valve PWM Refrigeration (Display cases) EC2 EX4-8 Expansion valve, Hot gas bypass, Condensing pressure and liquid regulator, Head pressure control, Suction/Crankcase pressure regulator, Heat reclaim (Capacity data as expansion valve) EXN Expansion Valve FX5-9 Expansion Valve Bi polar stepper motor driven Uni polar stepper motor driven Bi polar stepper motor driven Refrigeration, Air Conditioning, Water Chillers, Heat pumps Heat Pumps, Air Conditioning, Close Control Air Conditioning, Heat Pumps, Close Control EXD-U01 Driver Module EXD-SH1/2 Superheat Controller (Modbus) EC3-X Superheat Controller (TCP-IP) EC3-3 Coldroom Controller EXD-HP1/2 Superheat Controller (Modbus) EXD-SH1/2 Superheat Controller (Modbus) EC3-X Superheat Controller (TCP-IP) Selection Table for Electrical Control Valves and Applicable Controllers for CO 2 applications Valve type Function Capacity kw R744 Feature Main Application Applicable Controller CX2 Expansion Valve PWM Refrigeration (Display Cases) EC2 CX4-7 High pressure gas valve for gas cooler control Expansion device Hot gas bypass Head pressure control Suction/Crankcase pressure regulator Heat reclaim For capacity data for various applications (expansion, hot gas bypass etc.) please refer to the Controls Navigator Bi polar stepper motor driven Refrigeration EXD-U01 Universal Driver Module EXD-SH1/2 Superheat/ Temperature Controller 173

3 Electrical Control Valves Series EXM/EXL for OEM use, stepper motor driven Features Unipolar stepper motor Bi-flow (same performance in both flow directions in term of capacity) High MOPD: 40 bar in normal flow direction Removable coils in two versions: 12VDC/24VDC Continuous modulation of mass flow, no stress (liquid hammering) in the refrigeration circuit Linear flow Resolution: 500 pulses (half steps) or 250 full steps Hermetic design Reliability: 225 millions pulses at continuous 40 bar differential pressure Note: The valve is not released for refrigeration applications such as cold rooms and refrigeration display cabinets. EXM/EXL with Coil Selection Chart Type Part No.* Description Nominal Capacity kw R410A R134a EXM-B0A M Valve less coil EXM-B0B M Valve less coil EXM-B0D M Valve less coil EXM-B0E M Valve less coil EXM M Coil 12VDC EXM-24U M Coil 24VDC Connection size/style 1/4 ODM EXL-B1F M Valve less coil /4 ODF EXL-B1G M Valve less coil mm ODM EXL M Coil 12VDC EXL-24U M Coil 24VDC *Note: Only Bulk packing in boxes of 10 identical pieces The nominal capacity is based on the following conditions: Refrigerant Evaporating Condensing Subcooling +4 C (dew point) +38 C bubble point / +43 C dew point R134a, R410A +4 C +38 C 1K 1K Technical Data Max. allowable pressure PS MOPD Temperature range TS marking Weight Package and delivery 45 bar 40 bar in normal flow direction -30 to +70 C (liquid refrigerant) -30 to +60 C (ambient) Not required Valve EXM: 65 g, EXL: 76 g Coil EXM: 124 g, EXL: 156 g Bulk pack with 10 pieces Stepper motor type Full travel time Reference position Total number of pulses Insulation class EXM: A EXL: E Cable length Uni-polar, constant voltage 16.6 seconds at 30 pulse/sec. 5.5 seconds at 90 pulse/sec Mechanical stop at fully close position 500 half step (250 full step) 1m 174

4 Electrical Control Valves Series EXN For OEM use, stepper motor driven Features Unipolar stepper motor Bi-flow with same capacity in normal and reverse flow direction MOPD: 36 bar in both flow directions Unipolar stepper motor with gear mechanism enabling Bi-flow performance at 36 bar differential pressure across the valve Removable coil: 12 VDC Continuous, linear modulation of mass flow High resolution: 2000 pulses (half steps) or 1000 full steps Hermetic design Available driver with specified Software Rev. No. (or higher): - EXD-HP1: 0x EXD-HP2: 0x EXD-TEVI: 0x311C EXN with Coil Note: The valve is not released for refrigeration applications such as cold room and refrigeration display cabinet. Selection Chart Type Part No. (Single Pack) Description Nominal capacity [kw] R410A R32 R134a Connections Size / Style EXN-B2K Valve less coil /2 ODF EXN-B2L Valve less coil /2 ODF EXN Coil 12VDC, 5 wires The nominal capacity (Qn) is based on the following conditions: Refrigerant Evaporating Condensing Subcooling R410A, R134a, R32 +4 C +38 C 1K +38 C bubble / +43 C dew point 1K Technical Data Compatibility (not released for use with flammable refrigerants) MOPD (maximum operating pressure differential) Max. working pressure PS: Temperature range TS: liquid refrigerant Ambient Weight marking R410A, R32, 36 bar in normal flow 36 bar in reverse flow 45 bar C C Not required Valve EXN: 163 g Coil EXN: 158 g Stepper motor type Uni-polar, constant voltage, 5 wires Supply voltage 12 VDC coil: 12 V ± 10% Total number of pulses Pulsing rate frequency (pulse/sec.) Full travel time Coil insulation class Cable length 2000 half step (1000 full step) Hz 20 seconds at 100 Hz 10 seconds at 200 Hz A 1 m 175

5 Electronic Expansion Valves Series EX2 Pulse width modulated with exchangeable orifices Can be used with EC2 display case controllers Features Pulse width modulated Shut-off function eliminates the necessity of a separate solenoid valve Dampened plunger reduces noise effects of water hammer One valve body can be combined with 6 orifices to make 7 capacity ranges Applicable to all common refrigerants (HCFC, HFC, HFO/ HFO Blends) and for subcritical CO 2 applications Long lifetime, high reliability PS: 40bar, TS: -40 to +65 C Selection Chart EX2 with Orifice Capacity Q n at 100% open Valve (kw)* Type Part No. Description R134a R22 R404A R507 R744 R407F R448A R449A R513A R1234ze EX2-M EX2-I mm inlet / 12 mm outlet ODF 3 8 inlet / 1 2 outlet ODF EXO Orifice EXO Orifice EXO Orifice EXO Orifice EXO Orifice EXO-00X Orifice X ASC3 24V ASC3-230V Coil 24 VAC 50 Hz Coil 230VAC 50Hz * Orifice should be selected at max. 80% of Q n to allow covering the load fluctuation WARNING: R1234ze classified as A2L. Use of product only for non-explosive environment, non ATEX zone. Description Type PCN (single packing) PCN (bulk packing) Plug and cable assembly (1.5 m) ASC-N M Plug and cable assembly (3.0 m) ASC-N M Plug and cable assembly (6.0 m) ASC-N Plug PG9 Plug Plug PG11 Plug The nominal capacity (Q n ) is based on the following conditions: Refrigerant Evaporating Condensing, R407F +4 C (dew point) +38 C bubble point / +43 C dew point R22, R134a, R404A, R C +38 C R C -10 C R448A, R449A +38 C bubble point / +43 C dew point +4 C (dew point) +38 C bubble point / C dew point R513A, R1234ze +38 C bubble point / +38 C dew point Subcooling 1K For other operating conditions the selection tool Controls Navigator can be downloaded from or use correction factors with following formula: Q n = Q o x K t x K p Q n : Nominal valve capacity Q o : Required cooling capacity 176 K t : K p: Correction factor for evaporating and liquid Correction factor for pressure drop at valve (See Datasheet for Correction Factor Tables.)

6 Electronic Expansion Valves Series CX2 Pulse width modulated with exchangeable orifices for high-pressure CO 2 applications Can be used with EC2 display case controllers Features Pulse width modulated Shut-off function eliminates the necessity of a separate solenoid valve Dampened plunger reduces noise effects of water hammer One valve body can be combined with 6 orifices to make 7 capacity ranges up to 28.2 kw (R744) Long lifetime, high reliability PS: 90bar MOPD: 65 bar CX2 with Orifice Selection Chart Valve Orifice Nominal Capacity kw (R744) Type Part No. Type Part No. CX2-I EX0-00X CX2-I EX CX2-I EX CX2-I EX CX2-I EX CX2-I EX CX2-I Type Part No. Description ASC3 24V Coil 24 VAC 50 Hz ASC3-230V Coil 230VAC 50Hz * Orifice should be selected at max. 80% of Q n to allow covering the load fluctuation Coil Description Type PCN (single packing) PCN (bulk packing) Plug and cable assembly (1.5 m) ASC-N M Plug and cable assembly (3.0 m) ASC-N M Plug and cable assembly (6.0 m) ASC-N Plug PG9 Plug Plug PG11 Plug For other operating conditions the selection tool Controls Navigator can be downloaded from 177

7 Electrical Control Valves Series EX4, EX5, EX6, EX7 & EX8 Features Multifunction as expansion valve, hot gas bypass, suction gas throttling, head pressure, liquid level actuator etc. Fully hermetic design (no thread joints between valve body and motor compartment) Applicable to all common refrigerants (HCFC, HFC, HFO/ HFO Blends) and for subcritical CO 2 applications Stepper motor driven Short opening and closing time Very fast full-stroke time High resolution and excellent repeatability Positive shut-off function to eliminate the need for additional solenoid valve Bi-flow versions for heat pump applications High linear flow capacity Extremely wide capacity range (10 100%) Continuous modulation of mass flow, no stress (liquid hammering) in the refrigeration circuit Direct coupling of motor and valve for high reliability (no gear mechanism) Ceramic slide and port for highly accurate flow and minimal wear Europe patent No , USA patent No , Japan patent No Balanced force design Corrosion resistant stainless steel body and stainless steel connections PS: EX4-EX7 60 bar, EX8 56 bar Liquid Inlet Temperature TS: Uniflow: -50 to +100 C, Biflow: -40 to +80 C EX7 EX5 EX8 EX4 EX6 Selection Chart (Capacities see following page) Type Part No. Flow Pattern EX4-I Capacity Range EX6-M mm ODF 28 mm ODF Uni-flow EX7-I ODF ODF EX8-M % 42mm ODF 42mm ODF Inlet Connection Outlet Connection Electrical Connection 3 8 ODF 5 8 ODF EX4-M mm ODF 16mm ODF EX5-U (16mm) ODF 7 8 (22mm) ODF EX6-I ODF ODF EX7-M mm ODF 35mm ODF EX8-U (35mm) ODF (35mm) ODF EX8-I ODF ODF EX4-U (16mm) ODF 5 8 (16mm) ODF EX5-U (16mm) ODF 7 8 (22mm) ODF EX6-I Bi-flow (Heat Pump) ODF ODF EX6-M mm ODF 28mm ODF EX7-U (35mm) ODF (35mm) ODF M12 Plug Cable Connector Assemblies Type 178 Part No. EXV-M Temperature Range Length 1.5 m EXV-M C 3.0 m EXV-M m Connector type to valve Connector type to driver or controller M12, 4 pins Loose wires Illustration

8 Capacity Data Application Expansion Valve and Liquid Injection Valve Nominal Capacity kw (5% 100%) Valve Type R22 R134a R404A R410A R23 * R124 * R744 R407F R448A R449A R513A R1234ze EX EX EX EX EX WARNING: R1234ze classified as A2L. Use of product only for non-explosive environment, non ATEX zone. * Biflow versions are not released for R124 and R23 Capacity for biflow versions identical in both flow directions. The nominal capacity (Q n ) is based on the following conditions: Refrigerant Evaporating Condensing, R407F +4 C (dew point) +38 C bubble point / +43 C dew point R22, R134a, R404A, R410A +4 C +38 C R C +80 C R23-60 C -25 C R C -10 C R513A, R1234ze R448A, R449A +4 C (dew point) +38 C bubble point / +38 C dew point +38 C bubble point / C dew point +38 C bubble point / C dew point Subcooling 1K Guideline for Selection of Electrical Control Valves as Expansion Valves Controls Navigator For easy and quick selection of Electrical Control Valves as Expansion Valves, the Controls Navigator selection tool can be downloaded from the Internet at or use the quick selection tables on the following pages. The following guideline should be taken into consideration in order to obtain full advantages of the control valves: -- Published capacities are maximum and there are no reserve capacities -- Larger size of valve leads to shorter pull-down period and shorter travel time i.e., faster response. For example, the EX7 has a maximum travel time of 3.2 seconds. The valve has approximately 1.6 seconds travel time at 50% capacity operation. For controllers, see chapter Electronic Controllers and Sensors. Example: System with having two different operating conditions: A) 110 kw capacity at +4 C/+50 C with two stages compressor at 50% / 100% capacity B) 137 kw capacity at +4 C/+30 C with two stages compressor at 50% / 100% capacity The EX6 with 126 kw covers condition A, however is not sufficient to cover condition B. It is recommended to select larger valve i. e. the EX7 with 337 kw at condition A and 293 kw at condition B. Condition A: Full load ratio = 110 / 337 = 33% Partial load ratio = (110/2) / 337 = 16% Condition B: Full load ratio = 137 / 293 = 47% Partial load ratio = (137/2) / 293 = 23% The capacity ratios of system to valve are in all conditions higher than 10%. It is recommended to use the EX7 rather than the EX6. 179

9 Application Hot Gas Bypass - Nominal Capacities (kw) Valve Type Kv. m 3 /h R22 / R134a R404A / R507 R448A R449A R513A R1234ze EX EX EX EX EX The nominal capacity (Q n ) is based on the following conditions: Refrigerant Evaporating Condensing +38 C bubble point / +43 C dew point Subcooling Pressure Drop (For suction (For liquid Isentropic efficiency R22, R134a, R404A +4 C +38 C R513A, R1234ze +38 C dew 1K 0.15 bar 0.35 bar 0.5 bar 80% C dew R448A, R449A C dew For other operating conditions use the Controls Navigator selection tool (download from or use the following quick selection tables. Biflow versions are not released for hot gas bypass applications. EX4.. EX8 must be installed with motor downward in hot gas line applications. This ensures the valve life expectancy. Install a check valve on main hot gas line just after branch to Control Valve. 180

10 Application Suction Pressure Regulation (Evaporating or Crankcase Pressure) - Nominal Capacities (kw) Valve Type Kv. m 3 /h R22 / R134a R404A / R507 R410A R448A R449A R513A R1234ze EX EX EX The nominal capacity (Q n ) is based on the following conditions: Refrigerant Evaporating Condensing +38 C bubble point / +43 C dew point Subcooling Pressure Drop (For suction (For liquid Isentropic efficiency R22, R134a, R404A +4 C +38 C R513A, R1234ze +38 C dew 1K 0.15 bar 0.35 bar 0.5 bar 80% C dew R448A, R449A C dew For other operating conditions use the Controls Navigator selection tool (download from or use the following quick selection tables. Biflow versions are not released for hot gas bypass applications. EX4.. EX8 must be installed with motor downward in hot gas line applications. This ensures the valve life expectancy. Install a check valve on main hot gas line just after branch to Control Valve. Example: The EX6 provides 3.5 kw at 0.15 bar pressure drop with R404A or 3.5*1.41=4.9 kw at 0.3 bar pressure drop. Multiply above nominal capacities by following factors to obtain capacities at different pressure drops: Typical Order Package 1) Valve EX6, EX7 or EX8 Plug and cable assembly EXV-M60 2) Controller Kit EXD-U01 Part No P, bar Correction factor

11 Application Condensing Pressure Regulation and Liquid Duty - Nominal Capacities (kw) Valve Type Kv. m 3 /h R22 R134a R404A R448A R449A R513A R1234ze EX EX EX EX EX The nominal capacity (Q n ) is based on the following conditions: Refrigerant Evaporating Condensing +38 C bubble point / +43 C dew point Subcooling Pressure Drop (For suction (For liquid Isentropic efficiency R22, R134a, R404A +4 C +38 C R513A, R1234ze +38 C dew 1K 0.15 bar 0.35 bar 0.5 bar 80% C dew R448A, R449A C dew For other operating conditions use the Controls Navigator selection tool (download from or use the following quick selection tables. Biflow versions are not released for hot gas bypass applications. EX4.. EX8 must be installed with motor downward in hot gas line applications. This ensures the valve life expectancy. Install a check valve on main hot gas line just after branch to Control Valve. Multiply above nominal capacities by following factors to obtain capacities at different pressure drops: P, bar Correction factor Example: The EX6 provides 30kW at 0.35bar pressure drop with R404A or 30*0.76=22.8 kw at 0.2 bar pressure drop. 182

12 Application Hot Gas Flow such as Heat Reclaim Application - Nominal Capacities (kw) Valve Type Kv. m 3 /h R22 / R134a R404A / R507 R410A R448A R449A R513A R1234ze EX EX EX The nominal capacity (Q n ) is based on the following conditions: Refrigerant Evaporating Condensing +38 C bubble point / +43 C dew point Subcooling Pressure Drop (For suction (For liquid Isentropic efficiency R22, R134a, R404A +4 C +38 C R513A, R1234ze +38 C dew 1K 0.15 bar 0.35 bar 0.5 bar 80% C dew R448A, R449A C dew Valves must be installed with motor downward in hot gas line applications. This ensures the valve life expectancy. Bi-flow versions are not released for hot gas flow applications. 183

13 Electrical Control Valves Series EX4, EX5, EX6, EX7, EX8 Technical Data Compatibility * HCFCs, HFCs, HFO/HFO Connections ODF stainless steel fittings MOPD (maximum operating pressure differential) Max. allowable pressure, PS Medium range: Uniflow version Biflow version Evaporating range: Ambient Storage CE marking EX4/EX5 EX6/EX7/EX8 Blends CO 2 Mineral and POE lubricants EX4/EX5/EX6: 40 bar EX7: 35 bar EX8: 30 bar EX4/EX5/EX6/EX7: 60 bar EX8: 56 bar Liquid inlet TS: C TS: C -100 C to +40 C (uniflow version) C C not required required, Cat I, Module A Protection accordance to IEC 529, DIN Vibration for non-connected and fastened valve Shock Net weight Full travel time Seat leakage External leakage Package and delivery IP 67 with Alco supplied cable connector assembly 4 g ( Hz, 1 Oktave /min.) 20g at 11 ms, 80g at 1 ms 0.5 kg (EX4), 0.52 kg (EX5), 0.6 kg (EX6), 1.1 kg (EX7), 1.5 kg (EX8) EX4/EX5/EX6: 1.5 sec EX7: 3.2 sec., EX8: 5.2 sec Positive shut-off better than solenoid valve 3 g / Year Single pack, without electrical connector Salt spray test non-corrosion stainless steel body Humidity 5 95% R.H. * Valves are not released for use with inflammable refrigerants. Block Diagrams Superheat Control with EC3-X33 optional display unit ECD-002 Refrigerant Mass Flow Control with EXD-U 24 V~ K09-P00 ECP-024 Digital input EXD-U V or mA EX4 EX5 EX6 EX7 EX8 1 ECN-N60 sensor 4 PT5 pressure transmitter 6 Supply / Digital Input 9 Alarm out 11 EX4... EX8 valve 12 Suction pressure 4..20mA out 13 ECD-002 Display unit 184

14 Electronic Expansion Valves FX Series Emerson FX are stepper motor driven electronic expansion valves for precise control of refrigerant mass flow in air conditioning, heat pumps, close control, and industrial process cooling applications. Features Flexibility by configuration of outlet connection in 4 directions Stepper motor driven High resolution and excellent repeatability Linear flow capacity Extremely wide capacity range (10 100%) Continuous modulation of mass flow, no stress (liquid hammering) in the refrigeration circuit Direct coupling of motor and valve for high reliability (no gear mechanism) FX7 Selection table Type Part No. Inlet Connection ODF Outlet Connection ODF Electric Connection FX5-U FX6-I FX6-M mm 28 mm FX6.5-I FX6.5-M mm 28 mm FX7-U FX7.5-U FX8-I FX8-M42 42 mm 42 mm FX9-U Suitable for M12 plug (order separately) Cable and connector assembly Type Part No. Temperature Range Length Connector type to valve Connector type to driver board or controller Illustration EXV-M m EXV-M C 3.0 m M12 Loose wires EXV-M m Nominal capacities, kw Valve Type R134a R410A R22 R513A R1234ze FX FX FX FX FX FX FX Note: Nominal capacities of FX7.5/8/9 might be modified. Please contact sales office. Warning: R1234ze classified as A2L. Use of product only for non-explosive environment, non ATEX zone. The nominal capacity is based on the following conditions: Refrigerant Evaporating Condensing Subcooling R134a, R410A & R22 +4 C +38 C +4 C (dew point) +38 C bubble point /+43 C dew point R513A & R1234ze +4 C +38 C bubble point /+38 C dew point +4 C (dew point) +38 C bubble point /+38.6 C dew point 1K Note: For other operating conditions use the quick selection in this document or the Controls Navigator selection tool (download from 185

15 Bi-flow application FX valves are able to be operated in Bi-flow direction such as reversible heat pump with following consideration: Valve Max. Operating differential, bar Capacity Normal flow direction Reverse flow direction Normal flow direction Reverse flow direction FX FX Normal capacity on page 1 The same capacity FX Technical Data marking FX5/6/6.5: FX7/7.5/8/9: Compatibility (not released for use with inflammable refrigerants) not required required, Cat I, Module A HCFC, HFC, HFO, HFO-blends Mineral and POE lubricants Protection accordance to IEC 529, DIN Package and delivery (individual) Humidity Connections IP67 with EMERSON EXV-Mxx plug and cable assembly without electrical connector 5 95% r.h. ODF Copper Max. working pressure PS Ambient Storage FX5-8: 46 bar FX9: 35 bar C C Vibration resistance Evaporating 4g at Hz C Medium inlet TS: C Approval UL (pending) (pending) Electrical Data Stepper motor type Electrical connection Supply Voltage Driver supply voltage range Phase current, operating Bi-polar, phase current (constant current) 4 pin terminal via plug 24 VDC (nominal) VDC FX5-9: 800 ma Total number of steps Step mode Stepping rate FX5-7: 2400 full steps FX7.5: 2500 full steps FX8: 2600 full steps FX9: 3200 full steps Full step, half step or micro step 330 Hz Winding resistance per phase 3.4 Ohm ±10% Reference position Full travel time Mechanical stop at fully close position FX5-7: 7.3 seconds FX7.5: 7.6 seconds FX8: 7.9 seconds FX9: 9.7 seconds 186