CQR Grade 1 Door Contact, Surface, Non-resistored, 5 Terminal, White SC517/WH

Overview

Door contacts come in two parts: a contact housing on the frame and a magnet housing on the part that moves. This is the surface version, so both sit on the face of the frame and door.

This code is built for a security grade 1 job and a straightforward closed circuit, with no resistors to set.

How it works

• The circuit: with the door shut the circuit stays closed. Move the magnet housing away and the circuit goes open, which is what the panel sees.
• Single pole: SP means single pole. With no resistors in the part, any end of line values the panel asks for need planning separately.

Where to use it

Use it on windows and doors inside a building. An exposed door is outside what environmental class II covers.

It is not suitable for double doors, so look at a different code for a pair of leaves.

As a rule, many UK insurers and monitored systems look for a higher grade, so grade 1 suits a low-risk job. Check this before fitting it.

What the figures mean in practice

• Three pull-in figures: the gap depends on how the two parts approach each other, so the 20 mm figure applies only on the Z axis. Use the axis that matches how your door moves.
• -10°C lower limit: this fits unheated indoor rooms, within the indoor limit of class II.
• IP 3X: the 3 covers solid objects over 2.5 mm, and the X means it has no water rating.

Installing it

• Line up the parts: as a rule, fix the two housings so they sit side by side with the door shut, and keep to the gap for the axis you are using.
• Terminals: there are 5, so follow the markings on the part itself.
• Testing: as a rule, open the door with the panel in test mode and confirm the zone responds.

Planning your system

In most installations, a wired contact needs cable back to a zone on an alarm panel that accepts a plain normally closed input, so check that input first.

In practice, an intruder alarm is usually rated by its lowest graded part, so one grade 1 contact can limit the whole system. Designs often mix motion sensors with contacts to cover entry points.

Standards and ratings explained

• EN50131: the European standard series for intruder alarm systems, with grades that rise with the risk being protected. EN50131-2-6 is the part covering opening contacts.
• EN50130-5: the environmental test standard for alarm equipment, which is where class II comes from.