CDVI Digital Timer, 7-Day, DIN Rail Mount, 8 On/Off Schedules, 230Vac TH857

What this timer is for

Some doors should open freely during the working day and lock again afterwards. This CDVI unit handles that switching, so nobody has to remember to set the door.

It suits schools and other sites where free access runs to a known timetable. It sits on a DIN rail alongside the door's other equipment.

How it works

• Schedules: each ON/OFF pair is one window when the output changes state. Pre-set groups of days make it quicker to apply one pattern to several days.
• Battery backup: this keeps the clock running through a mains failure, so the schedule stays right afterwards.
• Manual override: useful for a one-off event or a closure, without changing the saved programme.

Where to use it

Indoors, inside a DIN rail panel or enclosure, since it runs on mains voltage.

A door released on a timer is open to anyone during that period. Make sure someone is on hand or the area is safe to leave open.

What the figures mean in practice

• Switching rating: check the rating label on the unit against your lock's load and voltage before wiring.
• 200 hours: that is a little over eight days of timekeeping without mains.
• 36 mm wide: allow this width on the rail, plus 65 mm depth inside the enclosure.

Installing it

Isolate the supply first, and keep the 230Vac wiring apart from low voltage door wiring. The timer's output usually goes through the lock circuit or a controller's free-access input, so check that equipment's instructions.

Planning your system

The timer does not unlock anything by itself. It needs a lock, such as a maglock or an electric strike, plus the lock's power supply and a way to open the door outside free access hours.

On an escape route, make sure the timer cannot stop the door releasing in an emergency. Agree this with whoever holds the fire strategy.