40T 96. INSTALLATION and OPERATION MANUAL 1 INSTALLATION 2 TECHNICAL SPECIFICATIONS. Dimensions and cut-out; panel mounting

Transcription

1 40T 96 UNIVERSAL TEMPERATURE and PRESSURE INDICATOR ALARM UNIT INSTALLATION and OPERATION MANUAL SOFTWARE VERSION.x (includes R77 version) code 864I / edition INSTALLATION Dimensions and cutout; panel mounting ,5 Panel mounting: Fix the device with the bracket provided before making any electrical connections. To mount two or more devices side by side, use the cutout dimensions shown above. CE MARKING: The instrument conforms to the European Directives 004/08/CE and 006/95/CE with reference to the generic standards: EN (immunity in industrial environment) EN (emission in residential environment) EN 600 (safety) MAINTENANCE: Repairs must be done out only by trained and specialized personnel. Cut power to the device before accessing internal parts. Do not clean the case with hydrocarbonbased solvents (Petrol, Trichlorethylene, etc.). Use of these solvents can reduce the mechanical reliability of the device. Use a cloth dampened in ethyl alcohol or water to clean the external plastic case. SERVICE: GEFRAN has a service department. The warranty excludes defects caused by any use not conforming to these instructions. 9 5! 70 For correct and safe installation, follow the instructions and observe the warnings contained in this manual. EMC conformity has been tested with the following connections FUNCTION CABLE LENGTH. USED TC input probe 0,8 mm compensated 5 mt PT00 input mm mt probe Power supply cable mm mt Relay output cables mm,5 mt 864I_MHW_40T96_070_ENG TECHNICAL SPECIFICATIONS Display Keys Accuracy Thermal drift Resolution (unction of settable sample ) Main input Thermocouples Cold junction error RTD type (scale configurable within indicated range, with or without decimal point) Max. RTD line resistance PTC type / NTC type Max nonlinearity error C / F selection Linear scale range Logic input Function of logic input s (Trip points) masking Relat contact Logic output Triac output Fault settings Transmitter / Sensor power Supply (option) Analog retransmission (option) Power supply (switching) Fuse (inside device, not operator serviceable) Faceplate protection Working / Storage temperat. Relative humidity Environmental conditions of use Installation Weight, 4 digit red LED s digit height 0mm ( digits), digit height 4mm (4 digits) mechanical keys (Raise, Lower, F) 0.% f.s. at 5 C, amb. temperature ts =0msec 0.005% f.s./ C 0msec, >4bit 60msec, >4bit (only for linear inputs) 0msec, >bit (only for linear inputs) 5msec, >bit (only for linear inputs) TC, RTD, PTC, NTC 60mV, V Ri MΩ; 5V, 0V Ri 0KΩ 0mA, Ri = 50Ω. adjustable digital filter J, K, R, S, T, B, E, N (IEC 584, CEI EN 60584, 60584) L GOST, U, G, D, C. Custom linearization available on request 0, / C DIN 4760 (PT00), JPT00 0Ω 990Ω, 5 C / KΩ, 5 C See tp parameter Faceplate configurable (with 4 digit display) (with digit display); punto Configurable decimal point position, possible segment linearization 4V, 5mA or novoltage contact configurable to reset memory latch, hold, flash, zero, select max./ min. peak, peakpeak value Maximum of three configurable alarms: absolute, deviation, symmetrical deviation. Adjustable hysteresis exclude on powerup latch reset from key and/or external contact insert delay filter (DON, DBI, DOF, DPO) set minimum intervention NO (NC) 5A 50Vac, 0Vdc 4Vdc, 0V at 0mA, limitation to 0mA Vac ±0%, A max. Snubberless, inductive and resistive load I t = 8A S states can be configured in probe fault condition 4V ±0%, 50mA 5V for transmitter, max. 50mA,V for potentiometer > 00Ω 0V Rmin 50K 0/4...0mA Rmax. 500Ω resolution bit (std) Vac/dc ±0%, 50/60Hz, 8VA (opt)...7vac/dc ±0%, 50/60Hz, VA 00 to 40VAC/DC type T500mA50V to 7VAC/DC type T,5A 50V IP65 0 to 50 C / 0 to 70 C 0 to 85% Ur non condensing for internal use only, altitude up to 000m Panel mounting, extractable from front 0 g for the complete version

2 DESCRIPTION OF FRONT PANEL Raise and Lower keys: These keys are used for any operation that requires a numerical parameter to be raised or lowered. The speed of change is proportional to the the key is pressed. The operation is not cyclic: once the maximum (minimum) limit is reached, there will be no further increase (decrease) of the value, even if the key remains pressed. The keys can be configured to perform reset, hold, display of the peak value, etc. as determined by the t.u. and t.d. parameters on the In menu. Function key: Gives access to different configuration stages Confirms any parameter changes PV display: Indication of process variable Indication of HI or Lo out of range Indication of open circuit (br) or short circuit (Er) Display of configuration and calibration messages Label with engineering units Indication of output states: OUT ( ); OUT ( ); OUT ( ); OUT 4 ( 4) 4 CONNECTIONS Generic user configurable outputs Out relay 5A/50Vac Out relay 5A/50Vac Outputs no 6 5 nc c Out Load Out Mod. 40T 96 R (base) Inputs Power supply Standard: 00 to 40VAC/DC ±0% Optional: to 7VAC/DC ±0% 50/60Hz, 8VA max. 0! PWR Mod. 40T 96 RR/RD/T0 (expandible) Modbus wires (Standard) 0 Serial line GND B (data ) A (data ) RS485 isolated serial line Modbus 4 wires / Cencal 9 0 Rx Tx For configuration Modbus 4 wires/cencal sees sheet technical Digital input Digital input 4V, 5mA or novoltage contact 6 5 External supply Analog retrans. output 0...0mA, Rmax. 500Ω 0...0V Rmin. 0KΩ Out4 relay 5A 50Vac Retransmiss. output/out4 8 7 R Generic user configurable outputs Out relay 5A/50Vac Triac Vac ±0% A max Out relay 5A/50Vac logic 4V/0mA, Out relay 5A/50Vac Standard: 00 to 40VAC/DC ±0% Optional: to 7VAC/DC ±0% 50/60Hz, 8VA max. Outputs Out Out Power supply 0 Out Load! PWR Inputs Thermocouples Linear input with wire transmitter Linear input with wire transmitter Available thermocouples: J, K, R, S, T, B, E, N, L, U, G, D, C Respect polarities For extensions, use compensated cable appropriate for thermocouple. Ri = 50Ω 4 VT 4V or 5V 4...0mA Ri = 50Ω 4 to connect for 0mA input VT 4V or 5V S Use wires of adequate thickness (min. mm ) PT00, JPT00, PTC, NTC Pt00 / PTC / NTC wire PT00 PTC / NTC / T wire PT00 T Linear input V for potentiometer 4,V R >00Ω Linear (I) dc current linear input 4 0mA, Ri = 50Ω Linear (V) dc voltage linear input 60mV, V Ri > MΩ 5V, 0V Ri > 0kΩ 864I_MHW_40T96_070_ENG

3 Connections for keylock function through digital input (require selection VT for the signal on contact ) 5 6 VT OFF (open): keyboard enable ON (closed): keyboard disable User configurable generic outputs / inputs ANALOGUE Output Analogue 0...0V, 0/4...0mA 0/...0V (SON), 0/4...0mA (SOFF) S is a jumper on the board for continuous or analogic output DIGITAL Input Digital input 4V 5mA (Jumpers S, S in position P) or from nonpowered terminal (Jumpers S, S in position N) S N S S P Modbus wires (Standard) Jumper position on board Serial line Modbus 4 wires / Cencal Jumper position on board S S OUTPUT BOARD CPU BOARD POWER SUPPLY BOARD Device structure: identification of boards DISPLAY BOARD OUTPUT BOARD Selection for the sensor or transmitter power supply V 5V 0V 5V 4V BA BA BA Jumper Directed Inverse A B A B OUT S ON OFF OFF ON OUT S ON OFF OFF ON OUT S ON OFF OFF ON S S S You can select output state to have direct or reverse mode. Jumper S, S and S are normally closed in position A. To change their state, the connection has to be removed. This operation must be done by trained technical personnel. Example in case of relay output: Direct mode: energized relay and related closed contact correspond to active trip point. Reverse mode: deenergized relay and related open contact correspond to active trip point. CPU BOARD POWER SUPPLY BOARD RTD, PTC, Transmitter NTC and Potent. Input Supply S ON OFF S OFF ON Jumper S4 is normally closed. To change its state, the connection has to be removed. This operation must be done by trained technical personnel. S0 S S LS S9 S S6 S8 S4 S7 S5 ACCESS TO THE MENU (S4) 864I_MHW_40T96_070_ENG

4 5 PROGRAMMING and CONFIGURATION LEVEL DISPLAY P.U. o. o. o. o.4 Process variable Setpoint Output Setpoint Output (*) Setpoint Output (*) Setpoint Output 4 (*) If NO JUMPER S4 (CPU) =ON (f sr In Pressed for approx. sec. Information display Hysteresis parameters Serial communication Input settings (*) For deviation alarms the setpoint range is If the Inc, Dec, F keys are not pressed within 5 sec., the display returns to the P.V. value 0v pa Output settings Password PA = 99 pr YES NO Protection code ln Custom linearization u.(. User calibration Keep the F key pressed to browse the menus. Release the F key to enter the displayed menu. Press the F key to access the parameters. Keep the F key pressed to exit any menu at any I_MHW_40T96_070_ENG

5 Hysteresis parameters (f Hysteresis parameters x. Hysteresis for trip point x. Hysteresis for trip point x. Hysteresis for trip point x.4 Hysteresis for trip point Information display f Information display ud Software version (o Instrument code xd Hardware Configuration OUT = Present For model digits sign: central segment OUT = Present OUT = Present OUT 4 = Present Central segment Sign Extinguished = None x Hardware Configuration Central segment Sign Ignited = Present ANALOG OUTPUT 5 = Present DIGITAL INPUT 7 = Present SERIAL COMM. = RS485 Serial communication sr Serial setting S. Virtual instrument inputs (o Unit identification code Inputs IN PV AL4 AL AL AL Bit Ex s.p ba Serial interface protocol Select Baudrate SP Serial protocol 0 CENCAL Gefran MODBUS RTU ba Baudrate Set code 48 in S.I to manage serial line PV and IN S.o Virtual instrument outputs 0... Outputs OUTW OUT4 OUT OUT OUT Bit 4 0 Ex. 0 0 Set code 9 in S.o to manage serial line OUT, OUT and OUTW pt Parity selection Pt Parity 0 No parity Ddd Even S.u Virtual instrument user interface Interf KEYB DISF LED LED LED LED OUT4 OUT OUT OUT Bit Ex Set code 65 in S.U to manage serial line KEYB and OUT 864I_MHW_40T96_070_ENG 5

6 TC/LIN input parameters In t.p Input settings Type of probe, signal and scale of main input Type Type 4 DIGIT DIGIT sign PROBE without dec. point with dec. point without dec. point with dec. point Probe: TC 0 TC J C 0/ / / /99.9 TC J F /8.0/999.9 /999.0/99.9 TC K C 0/00 0.0/ / /99.9 TC K F /7.0/999.9 /999.0/ TC R C 0/ / / / TC R F /8.0/999.9 /999.0/ TC S C 0/ / / / TC S F /8.0/999.9 /999.0/ TC T C 00/ / / / TC T F 8/ /75.0 8/ / TC B C 44/ /999.9 not available not available TC B F /7.0/999.9 not available not available TC E C 00/ / /750 not available TC E F 48/8 48.0/ /999 not available 4 TC N C 0/00 0.0/ /999 not available 5 TC N F /7.0/999.9 /999 not available 6 TC LGOST C 0/ / / / TC LGOST F /.0/999.9 /999.0/ TC U C 00/ / / / TC U F 8/ /75.0 8/ / TC G C 0/00 0.0/ /999 not available TC G F /47.0/999.9 /999 not available TC D C 0/00 0.0/ /999 not available TC D F /47.0/999.9 /999 not available 4 TC C C 0/00 0.0/ /999 not available 5 TC C F /47.0/999.9 /999 not available 6 TC C Custom Custom Custom Custom 7 TC F Custom Custom Custom Custom Probe: RTD 8 PT00 C 00/ / / / PT00 F 8/ / / / JPT00 C 00/ / / /99.9 JPT00 F 8/ 99.9/ / /99.9 Probe: PTC NTC PTC C 55/0 55.0/0.0 55/0 55.0/99.9 PTC F 67/ / / / NTC C 0/70 0.0/70.0 0/70 0.0/ NTC F 4/58 4.0/58.0 4/58 4.0/99.9 Probe: Voltage Current mV 999/ / / / mV linear custom linear custom linear custom linear custom mV 999/ / / / mV linear custom linear custom linear custom linear custom mA 999/ / / / mA linear custom linear custom linear custom linear custom mA 999/ / / / mA linear custom linear custom linear custom linear custom V 999/ / / / V linear custom linear custom linear custom linear custom V 999/ / / / V linear custom linear custom linear custom linear custom V 999/ / / / V linear custom linear custom linear custom linear custom V 999/ / / / V linear custom linear custom linear custom linear custom V/POT 999/ / / / V/POT linear custom linear custom linear custom linear custom 54 00mV...V 999/ / / / mV...V linear custom linear custom linear custom linear custom Probe: Custom PT00 PTC NTC 56 PT00 custom custom custom custom JPT 57 PTC custom custom custom custom 58 NTC custom custom custom custom N.B.: for the version R77 are not available the probe codes 0...9, , In case of nonavailability, maximum and minimum limits are set to 0. In case of custom linearization, test limits for setting LO and HI errors are given by the calibration values. If these limits are not exceeded, they are taken into consideration as limits LO_S and HI_S. (.. f.t f.d dp l.s x.s o.f d.. t.u. t.d. l.l x.l Select sampling (resolution). For linear input 0...V/POT only. Digital filter on main input Digital filter on process variable display Decimal point position for main input scale Minimum limit of main input scale and analogue output Maximum limit of main input scale and analogue output Offset correction of main input Select function of digital input Raise key function (active only in P.V.selection) Lower key function (active only in P.V.selection) Low limit for the alarms set point High limit for the alarms set point 0 0ms > 4bit 60ms > 4bit 0ms > bit 5ms > bit 4 to disable filter (average of the last eight values sampled) sec dp Format 0 XXXX XXX.X * XX.XX * X.XXX min max scale of input selected in t.p min max scale of input selected in t.p d. i. t. u. t. d. 0 None Zero Hold Flash 4 Max. peak display 5 Min. peak display 6 Delta peak display 7 Peak memory reset 8 Zero peak memory reset 9 s reset 0 Peak alarms reset Zero alarms reset Peak zero alarms reset Output status OUT 4 Output status OUT 5 Output status OUT 6 Output status OUT4 7 Keylock (d.i only) 8 Potentiometer Calibration ( t.u and t.d. only) 9 OFFSET (t.u. and t.d. only) L.S... H.S L.S... H.S (*) not available for TC, RTD, PTC and NTC scales 4 in order to visualize under the Ls value (Hs Ls) / 56 (only linear inputs not custom) Max. nonlinearity error for thermocouples (TC), resistors (PT00) and thermistors (PTC, NTC). The error is calculated as deviation from theoretical value and is expressed as percentage of full scale (in C). S, R range C; error < 0.% f.s. (t > 00 C) / for other range; error < 0.5% f.s. T error < 0.% f.s. (t > 50 C) B range C; error < 0.5% f.s. (t > 00 C) / range 44, ,9; error < % f.s. (t > 00 C) U range 99,9...99,9 and C; error < 0.5% f.s. / for other range; error < 0.% f.s. (t > 50 C) G error < 0.% f.s. (t > 00 C) D error < 0.% f.s. (t > 00 C) C range ; error < 0.% f.s. / for other range; error < 0.5% f.s. NTC error < 0.5% f.s. Tc: J, K, E, N, L error < 0.% f.s. PT00, JPT00 and PTC error < 0.% f.s I_MHW_40T96_070_ENG

7 Output parameters Custom linearization 0v Output settings ln Custom linearization of main input 0n Number of outputs 0 to Step 0 (beginning of scale value) Display limits (999 to 9999 for 4 digit display).t.t.t 4.t type (absolute only) type type type 4. t. t. t 4.t Value Direct Absolute or Normal or (high limit) Relative Symmetric Inverse to previous (window) (low limit) absolute 0 Direct Absolute Normal Inverse Absolute Normal Direct Relative Normal Inverse Relative Normal 4 Direct Absolute Symmetrical 5 Inverse Absolute Symmetrical 6 Direct Relative Symmetrical 7 Inverse Relative Symmetrical Step (end of scale value) Step the n step value corresponds to input: mv beginning scale n * DmV DmV = (mv full scale mv beginning scale) / Display limits (999 to 9999 for 4 digit display) mv beginning of scale (*) f.0 8 to disable on powerup until first alarm 6 to memorize to filter with F.O. mode (output filter mode) Output filter mode 0 not active: calculated status is sent directly to relay On delay (DON) On delay after it has been turned off (DBI) Off delay (DOF) 4 Delay for activation only at powerup (DPO) Step 4 mv end of scale Step 5 mv at 50 C (*) (*) 8 base max. 99 min (default = 99 sec) (*) only for tp = TC CUSTOM r.a delay for F.O. 0 to 99 min or sec User calibration t.m re Minimum output pulse 0 to 99 sec Disabled by setting value 0 Displayed if associated with at least one output Fault action (in case of damaged sensor) Er, br Value Out Out Out Out 4 0 OFF OFF OFF OFF ON OFF OFF OFF OFF ON OFF OFF ON ON OFF OFF 4 OFF OFF ON OFF 5 ON OFF ON OFF 6 OFF ON ON OFF 7 ON ON ON OFF 8 OFF OFF OFF ON 9 ON OFF OFF ON 0 OFF ON OFF ON ON ON OFF ON OFF OFF ON ON ON OFF ON ON 4 OFF ON ON ON 5 ON ON ON ON u.(. (.L. (.x. U.C. Function analog retransmission output Custom RTD sensor Custom PTC sensor 4 Custom NTC sensor 5 Potentiometer (0 to V) Calibration of minimum (*) Calibration of maximum (*) (*) when U.C. = press keys D to calibrate analog output Protection pr Protection code Value Displayed Modifiable parameters parameters 0 o., o., o., o.4 o., o., o., o.4 o., o. o., o. o. o. o. none 4 to disable In and Ou pages 8 to disable Cf; Sr page 6 to enable maintenance of reset latch at poweroff (for linear inputs only) base configuration (the following parameters will not be displayed: In: Ft, Fd, Of, L_L, H_L Ou: On [forced to no. outputs present], re) Ft, Fd, Of remain at set value L.L, H.L are forced to L.S, H.S 64 Virtual instrument 8 Disable of all the pages except P.A (Password) 864I_MHW_40T96_070_ENG 7

8 Hold function The input value and alarms are frozen while the logic input is closed. With logic input closed, a reset turns OFF both the relay outputs and the alarms latch. FLASH function Input value is sampled; state of alarms is not transferred to outputs; outputs are frozen. When the logic input is active the input value is frozen and the outputs are updated according to the calculated alarms state, including the ones latched. 6 ALARMS Normal absolute alarm Symmetrical absolute alarm AL AL AL H AL H AL AL [ H ] AL [ H ] alarm (*) inverse alarm directe For AL inverse absolute alarm (min.) with positive H, t = (*) = OFF if disabling on poweron exists For AL direct absolute alarm (max) with negative H, t = 0 For AL inverse absolute, symmetrical alarm with hysteresis H, t = 5 For AL direct absolute, symmetrical alarm with hysteresis H, t = 4 Normal deviation alarm (AL absolute, AL relative) Symmetrical deviation alarm (AL absolute, AL relative) ALAL AL AL AL H AL H ALAL AL ALALH ALH ALAL alarm alarm alarm alarm For AL direct absolute alarm (max) with negative H, t = 0 For AL direct relative alarm (max) with negative H, t = For AL direct absolute alarm (max) with negative H, t = 0 For AL symmetrical deviation alarm H, t = I_MHW_40T96_070_ENG

9 Filter outputs with reference to parameters F.0 and r.a The diagrams refer to a normal absolute alarm with hysteresis H = 0 F.O = DON = Delayed activation F.O = DBI = Delay in turning on output after output is turned off setpoint setpoint Variable Variable Output ra ra t < ra Output ra t < ra t > ra F.O = DOF = Delayed deactivation F.O = 4 DP0 = Delayed activation only at poweron setpoint Variable setpoint Variable Output Output ra ra ra ra Interface for GEFRAN instrument configuration KIT PC USB / RS485 o TTL Kit for PC via the USB port (Windows environment) for GEFRAN instruments configuration: Lets you read or write all of the parameters A single software for all models Easy and rapid configuration Saving and management of parameter recipes Online trend and saving of historical data Component Kit: Connection cable PC USB... port TTL Connection cable PC USB... RS485 port Serial line converter CD SW GF Express installation ORDERING CODE GF_eXK00 cod F I_MHW_40T96_070_ENG 9

10 ORDER CODE 40T 96 sign 4 NR. digits 4 0 power supply...7vac/dc Vac/dc transmitter power supply None 0 0 For T input (alternative to RTD, PTC, NTC),Vdc for potentiometer (**) (*) 0 5Vdc for transmitter (**) 5 4Vdc, 50mA 4 All (****) DIGITAL COMMUNICATION (**) None RS485 digital input / retransmission output (**) None Digital input OUT, OUT Analogue output 0...0mA (0...0V) (***) Both (***) Relay, Relay Relay, Relay Relay, logic Triac, Absent R R R R D T 0 OUT, OUT 4 (**) None 0 0 Relay, absent R 0 Relay, Relay (***) RR (* ) R77 for potentiometer input (Rinput >0Mohm (**) Not available in the case of output, output = R (***) Output 4 relay alternative to the retransmission output (****) Selectable (standard = 4Vdc) Please, contact GEFRAN sales people for the codes availability.! WARNINGS WARNING: this symbol indicates danger. It is seen near the power supply circuit and near highvoltage relay contacts. Read the following warnings before installing, connecting or using the device: follow instructions precisely when connecting the device. always use cables that are suitable for the voltage and current levels indicated in the technical specifications. the device has no ON/OFF switch: it switches on immediately when power is turned on. For safety reasons, devices permanently connected to the power supply require a twophase disconnecting switch with proper marking. Such switch must be located near the device and must be easily reachable by the user. A single switch can control several units. if the device is connected to electrically NONISOLATED equipment (e.g. thermocouples), a grounding wire must be applied to assure that this connection is not made directly through the machine structure. if the device is used in applications where there is risk of injury to persons and/or damage to machines or materials, it MUST be used with auxiliary alarm units. You should be able to check the correct operation of such units during normal operation of the device. before using the device, the user must check that all device parameters are correctly set in order to avoid injury to persons and/or damage to property. the device must NOT be used in inflammable or explosive environments. It may be connected to units operating in such environments only by means of suitable interfaces in conformity to local safety regulations. the device contains components that are sensitive to static electrical discharges. Therefore, take appropriate precautions when handling electronic circuit boards in order to prevent permanent damage to these components. Installation: installation category II, pollution level, double isolation only for low power supply: supply from Class or low voltage limited energy source power supply lines must be separated from device input and output lines; always check that the supply voltage matches the voltage indicated on the device label. install the instrumentation separately from the relays and power switching devices do not install highpower remote switches, contactors, relays, thyristor power units (particularly if phase angle type), motors, etc... in the same cabinet. avoid dust, humidity, corrosive gases and heat sources. do not close the ventilation holes; working temperature must be in the range of C. surrounding air: 50 C use 60/75 C copper (Cu) conductor only, wire size range x No 4 AWG, Solid/Stranded use terminal tightening torque 0.5Nm If the device has faston terminals, they must be protected and isolated; if the device has screw terminals, wires should be attached at least in pairs. Power: supplied from a disconnecting switch with fuse for the device section; path of wires from switch to devices should be as straight as possible; the same supply should not be used to power relays, contactors, solenoid valves, etc.; if the voltage waveform is strongly distorted by thyristor switching units or by electric motors, it is recommended that an isolation transformer be used only for the devices, connecting the screen to ground; it is important for the electrical system to have a good ground connection; voltage between neutral and ground must not exceed V and resistance must be less than 6Ohm; if the supply voltage is highly variable, use a voltage stabilizer for the device; use line filters in the vicinity of high frequency generators or arc welders; power supply lines must be separated from device input and output lines; always check that the supply voltage matches the voltage indicated on the device label. Input and output connections: external connected circuits must have double insulation; to connect analog inputs (TC, RTD) you have to: physically separate input wiring from power supply wiring, from output wiring, and from power connections; use twisted and screened cables, with screen connected to ground at only one point; to connect adjustment and alarm outputs (contactors, solenoid valves, motors, fans, etc.), install RC groups (resistor and capacitor in series) in parallel with inductive loads that work in AC (Note: all capacitors must conform to VDE standards (class x) and support at least 0 VAC. Resistors must be at least W); fit a N4007 diode in parallel with the coil of inductive loads that operate in DC. GEFRAN spa will not be held liable for any injury to persons and/or damage to property deriving from tampering, from any incorrect or erroneous use, or from any use not conforming to the device specifications I_MHW_40T96_070_ENG