re documento state of emergency uj gy gyv bollitore elettrico fuckteen www kladi it bridge cisco katia lele vandamme biglietto aereo catania milano modelle piccanti huichapan lavaggio camper torino shakespeare regine sicilia i consigli di bellezza di ovidio tesi scaricare tanganika giuseppe mango dior sun voglio sape na cosa usb 2 0 cardbus elettrostimolatori accessori plextor dvd black colgados agenzia immobiliare cesenatico www accessori bar it devoto oli dizionario dioi towers tifanny www estradas com caminhoes riciclaggio rifiuto acer lcd 19 pollici fragola eisner simone e matteo un gioco da ragazzi canon eos 350d efs 1855 ii intel pentium 4 660 vacanze agosto in tunisia toshiba mk8026gax la vie renato zero the bolshoi ballet hitachi travelstar 80gb toyota rav4 2003 dong thap crema capture trrg cry a river telefono telefonino cellulare shopping televisori a colori gigaset a345 convertitori file wma mp3 westen union carta per scrivere lettera ique 3200 navigatori gps koshu i leke taht www songs mp3 com nino rota la strada hp omnibook 6100 david bawie polo 1000 crow versace noir cellulare supporto auto nella mia citt marc alccol 120 download wallpaper marijuana batteria per motorola cd920 in dash amstrad nortek bluetooth dongle bmx jump debito pubblico statale samsung tv lcd 17 wankie pelicula tierra de osos progressivo coassiale scart cartolina festa mamma corsair value alfa 166 2000 new york minute decoder digitale tele system un filmato per chaos league sony mz nhf800 ati sapphire 9800 pro 128mb 256bit a festa massa martana david bowie the heroes eleonora rossi drago mas rapido mas furioso l fotos nike inter scuola estetica why you actin reggueton nad tuner sandi word cup 2002 the getway codici ps2 Vacanza francia Guaina isolamento termico Donne nude integrali Temi per cellulari Seiko orologio Esercizio gamba gratis dm/akipul.html Crostata nutella Findomestic Donna cerca uomo Foto annuncio sesso Svezzamento dm/jwidot.html Weight loss pills Tucson cose fare Poesia dediche dm/gxtcfg.html Torino escort Ordine architetto roma Calda figa Cohf Porno incesto gratis Chi l ha visto Foto ragazze nude in spiaggia Jessica biel dm/krlrvl.html Nudismo in italia dm/rrcqbi.html Foto michael schumacher Lenticchie Listino automobile Oculistica Cisti di baker Occasione auto Fighe super pelose dm/brbmph.html Invia sms animati gratis Credial carta di credito Accessorio xbox logitech Acquisto azioni Traduzione latino Nome dominio Anima gemella napoli dm/pqtrrk.html Dimensioni pene Offerta albergo mosca Nigeriane nude Travian Tgirl Chiesa cattolica italiana Melita toniolo sexy casalinghe Webank Lavatrici bosch Filmato erotico Dagosex Kate winslet sex dm/laaxnv.html Cerco casa magliana Gioco on line gioco Donne vecchie nude dm/kjcfml.html Video gratis xxx Automobile usato dm/ncsrme.html Video zoccole Vicenza chiesacattolica it Tuta folgore Coppia con lui cuckold Parma shopping Tavolo giardino sedia Offerta di lavoro amsterdam Big tits cum Foto gay neri Fessee Prestito pordenone Calcolo vincita lotto Esiti gare appalto dm/ksgsna.html Maxmara reggio emilia Apparizioni Albergo centro siviglia Xxx porno Foto hard gratis dm/bvljrv.html Alchimia del dolore Medio oriente Satana dm/wmusnv.html Foto figa piscia Kittim fenici Monica roccaforte Eva robins nuda Scuola vela altura dm/mixcou.html Creare collana dm/dhjdvw.html Dapaura rete imgv34 test personalita html Campagna toscana Slurp party Nissan murano Anteprima video porno gratis W disneychannel it dm/hrlkcv.html Forcella bici Mad max Create loghi Dragon ball z having sex Ayrton senna monaco Spiate sotto la gonna Federica tommasi escort Multichef ariete Fornelli smev dm/fsxcfn.html Vassoio Articolo regalo cristallo Raidue Van basco it gratis This article is about motorised valves used in Central Heating systems. Motorised valves are a type of electrically actuated valve (others include solenoid valves and valves using electrically-generated thermal effects).
Motorised valves generally comprise:
- a synchronous electric motor
- gears to reduce the speed and increase the torque output of the motor
The motor and gears are often combined in a package known as a Synchron motor.
- a linkage from the output gear to the hydronic part of the valve
- one or more switches (usually microswitches) actuated by, for example, a cam attached to the output linkage
- a spring: see below
- the above components usually comprise one module, often known as the 'head', which may be detatched from the parts below for repair or replacement.
- a valve controlling flow of water in the hydronic system, actuated by the head: this part is often known as the 'body'.
Configurations of motorised valve
Valves are commonly found in the following configurations:
The valve has 2 pipe connections (ports) and permits or blocks flow between the ports depending on whether it is actuated or not. Flow is permitted when the valve is actuated and blocked in its resting state.
The valve has 3 pipe connections, in a T formation. The centre leg of the T is the inlet and the two short arms are the outlets, usually referred to as ports A and B. Actuation controls whether the flow from the inlet passes to the A or B port. In the resting state flow is to the A port.
There are two types of 3-port valve:
- Diverter valve
- This is a simple change-over version of a 2-port valve: when the valve is actuated all flow is diverted to the B outlet.
- Mid-position valve
- In this type of valve there is a stable state in which flow from the inlet can pass to both (A and B) outlet ports simultaneously. This type of valve is commonly found in domestic central heating systems where it controls flow of hot water from a boiler to hot water and radiator circuits in a Y-plan system configuration.
Types of motorised valve
Spring return valves
In these types when power is applied the motor and gears act against the force of a spring to operate the valve. When power is removed the spring returns the valve to its resting position. In a 2-port valve this is the closed position. In a 3-port valve the resting position is where flow from the inlet passes to the A port.
These types of valve consume power whenever they are open (and, in the case of 3-port valves, often even when they are not). In 2-port valves the motor runs until the valve is fully open and then stalls as the actuator mechanism cannot move any further. 3-port valves are more complicated: a description can be found in the uk.d-i-y FAQ and here is a diagram showing a 3-port valve in a Y-plan CH system
Motor On / Motor Off (MOMO) valves
Since the motor only runs whilst the valve is changing from one state to another there is a saving in energy compared to valves where the motor runs continuously while the vale is open. Such valves may also be more reliable since the motor and surrounding components will run cooler.
ENERGISE ENERGISE TO CLOSE TO OPEN | | white yellow | | o o / / o/ o o/ o------- orange ----> TO BOILER | | | | ----------- ----------- | ------- | | | MOTOR | | | ------- | blue | NEUTRAL Switches are shown in their non-actuated states which occur when the valve is neither fully open nor fully closed. The switch on the left operates when the valve reaches its closed position. The switch on the right operates when the valve reaches its open position.
These types of valves are occasionally found in domestic central heating systems: usually as Satchwell or Sunvic valves with grey plastic heads. Sunvic manufacture both MOMO and spring-return valves in similar casings.
If a motor-open/motor-close valve is replaced by a spring-return valve, or vice-versa, the controls wiring must be modified to suit. In the case of replacing a spring-return with a MOMO valve this requires change-over contacts at the room thermostat (or progstat) and an extra wiring conductor between the 'stat and the valve.
|This type of valve is also found in non-domestic installations.|
Sunvic's SDMV series 3-port valves are motor-open/motor-close types but are wired identically to spring-return valves.
These Switchmaster valves with bright blue plastic heads are found in some older domestic installations. The author is unsure whether the wiring of these differs from that for spring-return valves.