Motorised Valves
la danzatrice di rio grande galerucella llegar a ti km 0 sorento www scanderebech it cartina calabria foto di daniele ronda telefoni cordless aladino the blood of fu manchu jason lee paulina www mi camcom it toyota mr2 opere di l sciascia bigiotteria fai te pandare dvd swing kids grabster pcmcia sodimm ddr pc2700 333 power stone 2 finanziamento limbiate urea producers la scala umana www infreschi avalanche express meteo venezia bac giang foto di sara casci etichette a rotolo trans tette malpensa express informazioni persona lg lacm8410r levin meyer imate jam gsm gprs pocket pc sharp xvz12000 www 155 it illusionismo giochi di prestigio numero seriale per the sims franzos karl emil cerco lavori edili frigorifero whirlpool side anfibi para crepuscolarismo all star jesolo negozi ati tv villaggio blu club di hurgada sitio de zaragoza rsmmc dv 256 mb nokia pallone basket molten reduce combattente di guerra band gang damned pps hard digiquest digitale terrestre bananan race drunk party www tvazteca topten wehrmacht ora zero un matrimonio ideale la favorita natalie cole chiama scanjet 3770c leona di lernia matura pic nigar khan nude emule per mac yvonne la francesina schede secure digital 512 acer easy mp3 reader symantec norton antivirus 2005 ita piazza stradivari michelle wild fantastic 80s aston martin db7 volante prestito arles la recensione di flight simulator 2000 professional edition penne usb radio mp3 eurolight ld6230 prima super 155 nintendo torre macauda tommy ricci europa vs italy francesca bacci fuga dal pubblicita esterna hotm ail com www one love blue it ricette con zucchini dlg juliana usb packard bell lettore xivd www esami lumsa it noche fria manico chitarra adult sex movie www beatles it trailer per axle rage inimioara driver disco removibili simac il gelataio gc 4000 buy shoes wuppenau prigionieri decapitati siemens cl75 negozi abbigliamento a catania guardia giurata feel da house mutuo tasso zero giovane coppia televisore al plasma dodge stealth anomalurus telecomando sony accessori per autoradio sony hi ilug shoah nellie valentina liquori fiere edilizia in italia numeri telefonici prato samsung 42d5s donna fra le belve sebastianelli orsk sei immagini per pacific storm abbigliamento sposa sulla sabbia black eyes peas hoensbroek jlenia multi cd impianti hifi hotel londra centro sin bandera vez appartamento vacanza roma video gay il nostro concerto toughbook cfm34 epson dfx5000 truman capote sanyo lcd crociera carnival incasso frigorifero combinato luna remix nirvana t shirt giulia montanarini video wu kiang cuore ballerino copertina mensile fox digitale piano toshiba notebook m40x 266 i pompini le sibille bomboniere per lazio www forzaitalia it hoover 3 6 panca piana disco esterno usb dina paucar dempo sfondi immagini decolonisation quebec www mukka net asciugatrici san juan ristorante latitude x1 frullatore acciaio pompini ingoio winna decan mouse ottici dedra sw archos mp3 player produzione felpe severina croatia gliwice lubriaco hard 18 everblue 2 samsung sgh e630 tinto brass it come stai vasco the informant foto sexy g f 5 punto natural katie price video bybank it tuttotesti com batteria sagem my x 3 officejet 6215 www libri nemo potest duobus dominis se bitdefender free edition video de mujeres denudas beautifoul modem bluethoot verbatim cdr 80 nicola legrottaglie d20 canon 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:
2-port
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.
3-port
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
In these types of valve the motor is used to drive the motor from one position to the next. Switches in the mechanism stop the motor when it has reached its desired position.
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.
2-port
This type of valve changes from it closed (off) to its open (on) position when power is applied to one terminal, and from open to closed when power is applied to another terminal.
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. |  Industrial 2-port motorised valve The large orange box on the right houses the motor and gears. The smaller orange box on the left contains the switches. |
3-port
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.
.jpg)
.jpg)
.jpg)