A good design should take the characteristics of the space into consideration, such as how often that space is occupied in order to determine the approach, which could be one of the following:
- Occupancy Mode
- Vacancy Mode
- Simple manual control using a wall switch
- Manual switching with delayed auto off
The basic premise is to have people manually turn the lights on. Often used for places which are not occupied for very long, where people come and go but not very frequently. Places that are infrequently used such as restrooms, elevator lobbies late at night, storage rooms, laundry rooms and so on.
Method of Control: Manual on, auto off.
Normally, sensors are used for motion, with infrared types being the most common, but basement parking is quite warm, and restroom is partitioned into stalls both of which diminishes the effectiveness of IR sensors unless the delay time is somewhat prolonged.
Solution: Lights can be turned on from any wall switch or by the use of sensors, after which a delay starts:
- Wall switches may still be used to turn the lights off manually, the sensor will enter standby mode after 30 seconds.
- If after the 30 second delay is up and there is no motion such as a hand being waved over the sensor then it means that no one is around, then the lights are turned off and the sensor enters standby mode.
In the past, sensors are quite commonly used, but having the sensor turn the lights on and off too frequently will only harm both the lamps and the relays controlling them, by shortening their lifespans. But there are times where the lights does not need to be turned only, but the sensors turn them on anyway which results in unnecessary wastage of energy. If this were to affect an infrequently used small room with only a few lamps, then it wouldn’t matter much, but if it were for a large area such as an elevator lobby, hallway or a restroom, then the lifespan of the lamps would be substantially be reduced. In addition, large capacity lamps such as gas discharge lamps, streetlights, where a long start up time is needed, then sensors are also inappropriate.
- Upon leaving, the occupant may manually turn the lights off; no need to wait for the delayed auto off to kick in.
- At night, from the bedroom to the bathroom, the lights will turn on automatically, but the lights can be turned off at the bedside manually (K15 with the push button switch)
- A long press on the push button connected to the K15 can have the lights remain on and temporarily ignore the sensor.
Application Area: Public spaces that are occupied for prolonged periods such as reception rooms, offices, workshops, classrooms, libraries and labs.
This is a supplementary capability to help turn the lights off to avoid wasting energy for public spaces when they are not occupied.
Method of Control:
- Lights can only be turned on manually
- When the occupant leaves they can turn the lights off manually; but if they forget then the auto off kicks in.
- If the delay off time is almost up, one needs only to wave at the sensor to extend the delay.
- The lights can still be forcibly turned off in instances such as when doing a presentation or when taking a nap.
- The lights need to be turned on manually from the switch.
- When the occupant leaves, they should turn the lights off manually, but if they forget, the controller will turn the lights off automatically. The purpose of vacancy mode is for when the occupant leaves and the room becomes vacant.
- If someone is just passing through and has no actual intention to turn the lights on, then it won’t turn on.
- If the lights need to be turned off then it can be, such as when making a presentation or taking a nap.
K20 Delay Switch
Area of Use: Hallway or stairwells; their primary use is for controlling the lights in long passageways or corridors. Push button switches should be installed along the length of the passageway for the convenient operation by the occupant.
Equipment: Multiple push button wall switches are installed along the length of the passage and connected in parallel, this would allow the lights to be turned on from anywhere and turned off from anywhere; anywhere a switch is installed. If the user forgets, the lights will still turn off automatically.