1
0814EN November 2016
T
hermo
-
elecTric
acTuaTors
T
hermo
-
elecTric
acTuaTors
N
ormally
o
peN
r478, r478m
Main characteristics
•
R478
thermo-electric actuators are equipped with a 2-conductors wire to
connect them to ambient thermostats or control units.
•
R478M
thermo-electric actuators are equipped with a 4-conductors wire for
a stroke-end micro switch to control circulators or zone valves (brown: phase -
blue: neutral- black and grey: micro switch).
• The R478VX121 and R478VX021 versions include a varistor for installation
in areas where the network voltage is subject to sudden changes that may
damage the electronic components.
Thermo-electric actuators normally open in heating and cooling radiant
panel systems are especially useful as they are not electrically fed for most of
the time, thus offering great energy saving levels.
Position mechanic indicator
R478 and R478M thermo-electric actuators include a position mechanical
indicator (A) on the top which enables to visually identify the current position
of the actuator and the valve it serves.
The actuator closes the valve when electrically powered.
The position indicator (A) lowers when the valve is closed.
The position indicator is particularly useful during testing to perform
operation verifications without activating the system or disassembling the
actuator.
A
Position indicator lifted =
thermo-electric actuator and
valve it serves open
A
Position indicator lowered =
thermo-electric actuator and
valve it serves closed
Description
Thermo-electric actuators installed on distribution manifolds, radiator
thermostatizable valves or fan coil units enable to adequately control the
ambient temperature by combining energy saving to high levels of comfort.
The R478 and R478M thermo-electric actuators feature absolute operational
quietness, a long life as they have no mechanical parts subject to wear and tear
and a proper slowed-down closing system to prevent water hammer effects.
The activation mechanism includes wax bulbs controlled by low-
consumption electrical PTCs.
Versions and product codes
Series Product code
Voltage
Characteristics
R478
R478X121
230 V
2-conductors wire
R478X122
24 V
R478VX121
230 V
2-conductors wire with varistor
R478M
R478MX021
230 V
4-conductors wire,
with stroke-end micro switch
R478MX022
24 V
R478VX021
230 V
4-conductors wire,
with stroke-end micro switch and varistor
Technical data
• Complies with B.T. directive provision and ENEC 03 certificate
• Status without voltage: normally closed (N.C.)
• Rapid connection for Giacomini standard valves and/or manifolds
• Position mechanic indicator
• Linear movement
• Valve useful lift: 2.4 mm
• Pollution class: II
• Nominal pulse voltage: 4 kV
• Protection class: IP40
• Protection against direct contacts through double insulation (Class II)
• Power wire: H05 VV-F; useful length 1,5 m
• Closing time at room temperature: ~ 6 mins.
• Room temperature of use: -5÷50 °C
• Storage room temperature: -20÷65 °C
• PBT self-extinguishing case material V0-UL94
• Normally closed microswitch with open valve (only for versions with stroke-
end micro switch)
R478
R478M
This appliance should not be operated
by children younger than 8 years, people
with reduced physical, sensory or mental
capacities, or inexperienced people who are
not familiar with the product, unless they
are given close supervision or instructions
on how to use it safety and are made aware
by a responsible person of the dangers its
use might entail.
Children must not play with the appliance.
It is the user’s responsibility to clean and
mantain the appliance. Children should
never clean or mantain it unless they are
given supervision.
