elect rical-engineering-po rt al.co mhttp://electrical-engineering-portal.com/lighting-circuits-connections-for-interio r-electrical- installations-2

Lig ht switch fo r inte rio r installatio n

Emmanouil Angeladas

Lighting Circuits Connections for Interior ElectricalInstallations (2)

Continued from first part: Lighting Circuits Connections for Interior Electrical Installations

IntroductionIn modern internal electrical installations, domestic and prof essional, there is a need f or lighting installationsin staircases and installation of emergency lighting that will operate in the event of interruption of electricitysupply f rom the grid.

The automatic staircase timer abolished Aller Retour switches to control the lighting of the staircase.

Of course, they can also be used as timers in other lighting and automation circuits (second consumption delay,e.g. bathroom ventilator, disengaging switch with a time delay).

Sometimes, a power failure might occur, due to a f ault in the distribution network or due to maintenanceissues. In some places such as hospitals, police and f ire departments, cinemas and theatres, major hotels andconf erence rooms, this power outage has unpleasant results.

In order to address this problem, apart f rom the main lightning, we also manuf acture an emergency lightingsystem which will be decribed in 3rd part of this technical article.

Automatic staircase timersSingle line diagrams, Analytical and Operating diagrams:

1. Light ing circuit controlled by an automatic staircase t imer (based on mercury)Description:

Lighting circuit of a large number of luminaires, which is controlled by an automatic timer (interruption andrestoration), operated by several points (instant contact pushbuttons). The circuit is mainly used in buildingsstaircases.

Go up to the Timers

General diagrams

Single line diagram

Lig hting c ircuit co ntro lle d b y an auto matic staircase time r - Sing le l ine d iag ram

Lig hting c ircuit co ntro lle d b y an auto matic staircase time r - Analytical d iag ram

ImportantNote: Wecanconnect inthe circuit(always inparallelway)severallights andas manybuttons aswe desire.

Analyticaldiagram

Go up totheTimers

Operat ing mode

Press any button and the coil is activated with the neutral being transf erred through that button to the end ofthe coil. At the other end of the button the phase is applied through the medium contact (2) of the mercurialampoule and the contact on the right end (3).

Once activated the coil repels the armature (and the whole system) upward. Theref ore the mercury bulbchanges posit ion shorting out the other two contacts (1) and (2).The phase is transf erred to contact (1),namely the luminaires.

Lig hting c ircuit co ntro lle d b y an auto matic staircase time r - Op e rating d iag ram

The coil is not enabled as long as we let the button and the armature descends due to the weight of thecartridge cavity.

The more closed the tap is, the more slowly the armature descends. This way we regulate the time the lightswill stay on.

Operating diagram

Obcservations

The automatic staircase timer (), is a combination of an alternative three posit ion switch and a time relay.The posit ions of the alternative switch are:

1st position: For automatic operation2nd position: Permanent discontinuation3rd position: Permanent operation (e.g. when we want to clean the stairway)

Go up to the Timers

Automatic operat ion

Pressing any instant contact pushbutton (B) , the control circuit closes and the time relay (KT) is stimulated,which subsequently and through the alternative switch closes the power circuit (main circuit), whereby lightsilluminate. Af ter a preselected time (as much needed to bring the hydraulic system of the timer in its rest position),power supply of the power circuit is turned of f , by opening the contact KT1 of the time relay.

Important note: By observing both the analytical and the operational diagram, we can see that the Neutral (N)is common f or the luminaries and the pushbuttons.

Go up to the Timers

Auto matic staircase time r

Staircase e le ctro nic time r ( 3 & 4 wire co nfig uratio n)

2. Light ing circuit controlled by an automatic staircase t imer (electronic)Staircase timers are applied in any residential or commercial buildingwherever automatic control is required on predef ined times.

Lighting control in staircases made with automatic t imers (bracket railprofile), mounted in electrical switchboards at the staircase and activated bypushbuttons with light or no indication located in various places of thestaircase or by motion detectors, which detect movements in the range oftheir surveillance and enable the automatic switch.

Go up to the Timers

2.1 Staircase electronic t imer (3 and 4 wire configurat ion)

Important Note: One contact of the lights is permanently connected to theNeutral and the other one is connected to the return (for the lights) of theautomatic t imer.

Operation mode

Staircase e le ctro nic multifunctio nal time r (3 and 4 wire co nfig uratio n)

When you press any button the automatic t imer is activated (the Neutral is carried through the button and at hisedges 230V voltage is applied) and the main contact closes f or as long as we have preselected. At that t ime thelights will illuminate. The phase is transf erred through the main contact of the automatic t imer to the other endof the luminaires.

Once this t ime has elapsed, the contact opens and the lights go out.

Important Note: One contact of the buttons is permanently connected to the Neutral and the other one isconnected to the return (for the buttons) of the automatic t imer.

Go up to the Timers

2.2 Staircase electronic mult ifunct ional t imer (3 and 4 wire configurat ion)

Automatic staircase timers are manufactured for certain lamp wattage.

They have timers so we can choose the interval we want them to be turned on. The multif unctional automaticstaircase timers have the option of continuous operation when a button is pressed f or more thantwo seconds and they can increase and decrease their luminance f or twenty seconds af ter the endof regulation time, as a warning that the lights will turn of f .

Also, they have the option (changeover switch) to pose the circuit of f or keep the lights permanently on.

Some of the automatic multif unctional t imers may have separate control input 8 240 V AC/DC, galvanicseparated (e.g. intercom) and they can also automatically detect the 3 or 4 wire conf iguration.

Important note:

The automatic staircase timers can be connected with incandescent lamps, halogen lamps, single f luorescentlamps and compact f luorescent electronic lamps.

The electronic staircase automatic t imers have some advantages over the older ones.

The most important of these are:

1. Wide range time adjustment.2. Great conf idence when they work as there is no f ear to get stuck while operating.3. High accuracy of repeatability of the time. Time does not change if no intervening setting.4. Their small size gives them the potential to be installed inside the staircases electrical panel.

Go up to the Timers

Lighting Circuits Connections for Interior Electrical Installations (2)IntroductionAutomatic staircase timers1. Lighting circuit controlled by an automatic staircase timer (based on mercury)General diagramsOperating modeAutomatic operation

2. Lighting circuit controlled by an automatic staircase timer (electronic)2.1 Staircase electronic timer (3 and 4 wire configuration)2.2 Staircase electronic multifunctional timer (3 and 4 wire configuration)