Merlin GerinCommand and control productsEconomically lighting stairwells and hallways up to 2300W, with switch off warning.

Datasheet:LO6

Problem Stairwells and hallways need to be well lit butonly when people are present. A considerableamount of energy is wasted if the lights are lefton permanently, with no one present. Equally people do not wish to find that thelights suddenly go out without any warning.

Persons entering the stairwells and hallwaysswitch the lighting ON as normal. A relay in thelighting circuit maintains the lighting ON until,after a pre-set time, the lighting level is reduced to50%. After a short time period at this reducedlevel the lighting is switched OFF. Should personsbe present during the 50% light level period thereis adequate warning, and light, to reach a switchand put the lighting level back to full.

This circuit arrangement is suitable for 220/240V 50Hz single phaseincandescent lighting loads up to 2300W, excluding ELV halogen lamps.The time period that the lights stay on FULL after a switch is pressed,can be set from 1 to 7 minutes. The 50% lighting period can be set from20 to 60 seconds.

A retractive, pushbutton type switch should be located wherever thearea may be entered. These switches can be standard 86mm squareformat or grid / modular arrangement. All switches must have their normally open contacts wired in parallel but there is no restriction onhow the looping is achieved or how many switches are in the circuit.Neon indicators (or other indication up to 10W total per circuit) may beconnected across the switch contacts to help locate the switches in thedark. Standard light switches must not be used. The switching circuitonly carries current during switching so considerations of cable rating orcable bunching are greatly simplified. Calculations for the main circuitare also much easier as only the main cable run has to be considered.

For lighting circuits protected by a 6A or 10A MCB the circuit would bewired in 1.0 or 1.5mm2 cable. There is no need to provide control circuitprotection if the switch circuit cable is the same size as this main cable.The relay has an override switch on the front allowing the lighting to beswitched ON permanently for maintenance periods.

Solution

2000W of lighting left on for 8 hours every night consumes 5840 kWhper year at a cost of £408 assuming 7 pence per unit. Most of this costcan be saved every year if the lights are only on for short periods oftime, as required. The original equipment cost will be paid back wellwithin the first year. This part of the installation would be eligible underthe Enhanced Capital Allowance Scheme.

Savings

Ordering information

Technicaldetails

SwitchcircuitTo luminaires

3

4

N

P

MIN

N

PRE

Symmetrical DIN rail mounted devices for easy installation.

Description ReferenceMIN "Staircase" timer 15363PRE pre warning device 15376

The MIN timer relay plus the PRE occupies the same space as a double pole miniature circuitbreaker and may be fitted on to the DIN rail portion of an Merlin Gerin type A or B Multi servicedistribution board. Alternatively the relay may be fitted in an individual enclosure.

Description IP rating Referencesurface mounted enclosure for one or two relays IP30 13392Many other enclosures of different sizes and IP ratings are available. Please ask for details.

Suitable switches for these circuitsMK Logic Plus: K4878P WHI (plus neon K3041 if required), Architrave K4848P WHI.

Timer Relay type: MIN

■ Relay suitable for 220/240v 50Hz

■ Time setting: 1 to 7 minutes in 15 second intervals

■ Contact breaking capacity: 16A at pf=1.0

■ Maximum load of incandescent lighting: 2300W at 240v 50Hz

■ Terminal capacity: up to 6mm2

Timer PRE

■ For use with MIN timer relay

■ Time setting (50% light level) 20, 30, 40, 50 or 60 seconds

■ Terminal capacity: up to 6mm2

Note: This equipment is not compatible with fluorescent or ELV halogenlighting.

Note: The switch on the side of theMIN timer must be set to position 4.

Schneider Electric Ltd, Merlin Gerin Low Voltage Devices, Fordhouse Road, Wolverhampton WV10 9ED. Tel: (01952) 290029 Fax: (01902) 303366. Internet address: http://www.schneider.co.uk

CON5057 Aug2001

E Energy management.

L Lighting control.

T Time management.

M Measurement.

C Control circuit techniques.

Subjects covered will fallinto the following main categories:

The guides will cover:■ The problem or difficulty.

■ The solution, explanation and possible options.

■ Technical information.

■ Wiring diagrams and/or photograph.

■ Product ordering information including recommended enclosures.

Please submit suggestions for these application guides, especially if you have a problem for which you require a solution.

If you have a problem and require a solution, please fax: 01902 303400.

Application Overview Schneider Electric are producing a series of Merlin Gerin command and control applicationguides. They will provide economic and innovative solutions to electrical control problemscommonly found in the course of building designand contracting work.

It is intended that these guides stimulate specifiers and design-build contractors to think differently about the way thatcircuits are designed. In many instances the addition of components in the distribution board can save considerablewiring time on site.

Contractors will be given ordering information, wiring diagramsand guidance on installation of the equipment recommended. Each application guide will normally apply to a single circuit sothat the solutions are kept simple and easy to understand.