Specifications

11
17. Is there any
method of
controlling a
RadioLINK
system?
18. BS 5839: Pt.6
says that all
alarms must be on
one final circuit.
Will RadioLINK
comply with this?
A fixed wall switch, Ei411, is available. This allows Test and Locate features to be incorporated
into a RadioLINK system without having to reach up to the alarms. The switch is the same size
as a normal light switch and is powered by Lithium cells having a realistic 10 year life. This
means that the switch is easily installed, as it does not require any wiring, the signals to the
alarms being transmitted by a radio link. A Manual Call Point, Ei407, is available for use in
larger installations. This also has the benefits of a Lithium cell power supply and no wiring
connections being required.
In applications where a relay is required to signal to other devices the Ei428 is available. The
Ei428 is mains operated, but has a rechargeable Lithium cell back-up supply to ensure that it is
operational even in a mains failure. This is an essential requirement when signalling to Warden
Call Systems. The unit is supplied with a cover to enable it to be sited at any convenient
position within the property.
The 1995 version of BS 5839: Pt.6 was worded to effectively preclude the use of RadioLINK, as
it required that all alarms should be on a single final circuit. The 2004 revision of the standard
recognises the benefits of radio communication in the note to Clause 15.5 dealing with power
supply requirements for smoke alarms, thus: “This recommendation [for a single final circuit]
does not apply if the form of interconnection is not capable of conducting current, e.g. if the
means of interconnection comprises radio communication rather than wiring”.
Building Regulations Document B (England & Wales) allows the use of a radio link between
alarms under section 1.21. The Building Regulations in Scotland and Northern Ireland
currently make no reference to a radio link, but it is considered that the new recommendations
of BS 5839: Pt.6: 2004 would be an acceptable means of meeting the requirements of
both documents.
Yes, the individual smoke alarms and RF bases are not electrically connected so a phase
difference will not affect them. The only connection between the alarms and bases is by a
radio signal.
19. Can the smoke
alarms be
connected on
different phases
of the mains
supply?