FEATURES
N
OTE:
-
For correct operation, it is very important that the
t
otal load
M
UST NOT
b
e less than the minimum power/load
rating
AND MUST NOT be greater than the maximum
p
ower/load rating marked on the dimmer. This rating is shown
in Watts (W) & Volt/Amps (VA) on the back of each dimmer.
Soft Start When the dimmer is switched on, the brightness of
the lights will be gradually increased over a period of 1 to 3
seconds until a pre-selected level (set by the control knob, is
attained.
This feature alone will help to greatly extend the life
expectancy of filament lamps, by avoiding the initial power
surge.
Overload Protection If any of the dimmers are overloaded,
the output to the lamp(s) will be automatically reduced to
provide protection against damage to the dimmer and to the
installation. An Intelligent Power Monitoring System (IPMS) is
used to provide protection from overload by reducing power
levels to the load(s) in stages according to the severity of the
overload, as follows: - (Note; The first figures given are the
appr
oximate load on the dimmer as a percentage of its
maximum rating.)
4
8
3
7
2
6
Intelligent Dimmer Switch
These dimmers comply with both
BS EN 60669-2-1 & BS EN 55015
Please keep this leaflet for future reference
5
SAFETY INSTRUCTIONS
• This product must be installed by a competent person in
accordance with the current editions of the IEE Wiring
Regulations (BS7671) and Buildings Regulations. If in any
doubt, consult a qualified electrician.
• To prevent electrocution, do not work on any appliance
live. Turn off the mains supply before commencing work.
• If this product has a metal front plate it must be earthed.
• To prevent fire hazard do not exceed the rated load
specified for the product.
• The minimum box depth required for white plastic dimmers
when using the supplied pattress is 16mm.
• Single white plastic dimmers without a pattress, as well as
all other dimmers with front plates of at least 9mm deep,
the minimum box depth required is 25mm.
• Double dimmer in a one-gang plate require a minimum box
depth of 35mm
44157 PL Ed. 2
• All dimmers with a front plate less than 9mm deep require
a
minimum box depth of 35mm.
•
Dimmer switches must not be used in bathrooms,
washrooms or any location subject to splashes of water
condensation or dampness.
•
Product and packaging should be disposed of via standard
refuse facilities at the end of their life.
GENERAL INFORMATION
• Dimmers are available with one or two modules mounted
on the same fr
ont plate. Dependent on power output, they
are also available in one or two gang front plates with
single or double dimmers.
• The control knob(s) has a push on/push off action. Rotation
of the knob(s) will vary the light setting.
• The terms one-way and two-way switching refer to the
mode of switching required in an installation.
• One-way switching is used in installations where a circuit is
contr
olled by just one switch. e.g. controlling one light
fr
om a single switch which is either on or off.
See Figur
e 1
.
• Two-way switching is applied to installations where a circuit
is often controlled by two switches, e.g. controlling a light
circuit from two switches located some distance apart, one
switch at one end of the room and another switch at the
other end.
• MK intelligent dimmers have two-way switching, which
a
llows their use in either application.
•
In a two-way installation as shown in
f
igure 2
,
only one
dimmer must be used. A standard 2-way switch must be
u
sed in the other position.
• As long as the rotary control knob is not turned, when
pressed, the dimmer will switch on at the previously set
light level. This is also true in the two-way set up described
above and shown in
Figure 2, even when operated by the
remote switch.
• To avoid damage to the dimmer, do not operate outside its
maximum and minimum wattage, or Volt/Ampere limits.
These limits are given on the rear of the dimmer, on the
packaging and in the Specification section below.
• The dimmers should not be installed where an ambient
temperature is outside the 0ºC & 40ºC limits.
NOTE: It is normal for the front of the dimmer to become
quite warm in use, the temperature reached being
dependent upon the lamp load and the ambient
temperature.
• MK dimmers employ the latest technology, using micro-
controller based circuitry to provide the features described
in the following section.
Up to 125 Load will receive maximum power continuously.
>125 to 150 Output to the load will be reduced to 50% of
the maximum after a delay of appr
oximately 20
seconds after switch on.
>150 to 200
Output to the load will be reduced to the
minimum setting after a delay of approximately
20 seconds after switch on.
>200 Output will be disabled (dimmer will switch off)
almost instantaneously after switch on.
Nor
mal operation will r
esume after the dimmer is switched of
f
and turned back on, with the load adjusted to be within its
maximum and minimum ratings.
COMPATIBILITY WITH LOW VOLTAGE LIGHTING SYSTEMS
One for
m of Low V
oltage Lighting System comprises a good
quality wir
e wound step down transfor
mer for Low V
oltage
Lighting loaded with suitable Low Voltage Tungsten Halogen
lamps(s). Another for
m comprises a fully dimmable Electr
onic
Transformer, specifically designed for dimming using phase
delay, phase-cut-on or leading edge type of dimmer, loaded
with suitable Low Voltage Tungsten Halogen lamp(s).
The dimmers are designed to work with a large number of
fully
dimmable
, good quality, Wire Wound as well as Electronic Low
V
oltage Lighting T
ransformers, which are recommended for
use with phase delay, or leading edge type dimmers.
DO NOT
use transfor
mers that are only suitable for use with phase cut,
phase cut-off, or trailing edge type dimmers.
So as not to compr
omise system safety
, MK r
ecommend that
transformers have built in thermal protection and have over-
current protection on both primary and secondary circuits. The
L
V system must comply with the EMC dir
ective and car
r
y the
CE marking. The total
transformer load on the dimmer
(obtained by adding together the load rating of each
transformer) must be within the minimum and maximum load
rating W/V
A of the dimmer.
In addition, transformers MUST be loaded correctly and they
must provide correct loading to the dimmer, within its specified
minimum and maximum Power/Load ratings.
For optimum performance of the dimmer, load each
transformer with lamp(s) so that the total load on each
transfor
mer is between 75 - 100% of its rated load. (e.g. load a
transfor
mer rated at 25 to 105W/V
A with lamps, so that their
total wattage adds up to 80 to 105 watts.)
NOTE: Some transformers for low voltage lighting have
input circuits which, when used with phase delay type of
dimmers, r
esult in ver
y high peak power pulses in the
dimmer. To avoid overloading and possible malfunctioning
of the dimmer
, do not connect more than the maximum
number of transformers specified below, to any one
dimmer
.
Up to 300W/240VA dimmers - Max. 4 transformers.
Over 300W/240V
A dimmers - Max. 5 transformers.
The dimmer's micro-controller based circuitry monitors the
essentially a.c. supply conditions r
equir
ed for wir
e wound
transformers and if a d.c. supply condition is detected due to
some fault, which could overheat and damage the transformer,
the dimmer automatically turns off the supply to the
transformer after a short period.
COMPATIBILITY WITH MAINS VOLTAGE HALOGEN LAMPS
The soft start feature incorporated in this range of dimmers
makes them ideally suited to drive mains voltage halogen
lamps, which have inherently high inrush currents at switch on.
By using a soft star
t with this type of load(s), not only is the
dimmer protected against premature failure but the lamp(s)
load also benefits fr
om pr
olonged life due to limitation of the
life shortening high inrush currents at switch on.
Failur
e to comply with the pr
e-r
equisites given above could
compromise System Safety.
None of these MK dimmers are suitable for use with
fluorescent lighting, including energy saving lamps.