ERT20T
Room
Heating
Setback input.
Product Compliance
This product complies with the essential requirements
of the following EC Directives:
• Electro-Magnetic Compatibility Directive 2004/108/EC
• Low V
• EC Marking Directive 93/68/EEC
SAFETY INFORMA
These instructions are applicable to the Salus Controls
model stated on the front cover of this manual only
must not be used with any other make or model.
These instructions are intended to apply in the United
Kingdom only
other statutory obligations.
This accessory must be fitted by a Competent person,
and installation must comply with the guidance
provided in the current editions of BS7671 (IEE Wiring
Regulations) and Part ‘P’ of the Building Regulations.
Failure to comply with the requirements of these
publications could lead to prosecution.
Always isolate the AC Mains supply before
opening or removing the unit fr
wall box.
Please leave these instructions with the end user where
they should be kept in a safe place for future reference.
INTRODUCTION
A thermostat is a device that is used to switch the
heating system in your home on and off as needed. It
works by sensing the air temperature and switching on
the heating when the air temperature falls below the
thermostat setting, and switching it off once the set
temperature has been reached.
The ERT20T T
Controls is a stylish and
accurate electronic thermostat
with a large, easy to adjust
setting dial. The thermostat
has been specifically designed
to be used in underfloor
heating applications.
FEA
• V
• 2°C/4°C selectable Night Setback (NSB) function
• Noiseless thermostat
• Heat/Cool switch
• PWM On/Off control
• Local Mode and Communication Mode
• Solid State (T
• Stylish casing
• User friendly
Installation
Please read the important safety information at the start
of this manual before you begin to install the device.
The ideal position to locate the ERT20T T
room thermostat is about 1.5m above floor level. It
should be mounted in a location where the thermostat
is easily accessible, reasonably lit and free from extremes
of temperature.
The electrical connections to the ERT20T T
to the internal terminal strip. Connection details are
shown below - no Earth connection is required for the
correct and safe operation of the thermostat as the
device is double insulated.
Electrical Connections
T Description Wiring Diagram
Switched Output
L Mains Live
N Mains Neutral
Night Setback (NSB
- 230V AC input)
After installing the ERT20T T
wiring connections can be made as shown above. The
following criteria apply to the installation:
• The incoming AC mains supply should be 230V AC and
fused at 2 amps.
• Optimum cable size for installation is 1.5 mm
2
; wiring
colours should be in accordance with the current
requirements of the IEE Wiring Regulations.
• All wiring connections should be securely made, and
be firmly terminated within each of the terminal screw
clamps.
Do not restore the mains supply to the system until all
associated items are fully installed.
NOTE: All electrical installation work should be
carried out by a suitably qualified Electrician or
other competent person.
If you are not sure how to install this thermostat consult
either with a qualified electrician, heating engineer or
your boiler / heating system supplier for advice on how
to continue.
Do not remove or r
wiring without the mains supply to the
system being isolated.
Switch and Jumper Settings
Changes to the switch or jumper settings should
only be made by the Engineer carrying out the
installation or other qualified person.
The installer should select the switch or jumper positions
required if changes need to be made to the factory
default settings.
Switch Position Function
SW1 HEA
COOL – Cooling system
Jumper Position Function
4C – 4 °C Setback (default)
2C - 2 °C Setback
PWM ON – PWM output (default)
OFF – On/Off output
VP ON - Enable (default)
OFF - Disable
NOTE: If switch SW1 is set to ‘Cool’, PWM mode is
automatically disabled. In this case the ERT20T T
only operate in On-Off mode, even if the PWM jumper
is set in the ON position.
Operation
The ERT20T T
itself,i.e DIP switch setting (this
is called Local Mode) and is
adjusted very easily by turning
the rotary dial on the front of
the thermostat to the required
temperature setting. T
the set temperature, turn the
rotary dial to the left to set a lower temperature, or to
the right to set a higher temperature.
The orange Light Emitting Diode (LED) backlight will
light when the temperature is below the set value,
showing that the thermostat is calling for heat or
cooling from the system. Once the room reaches the set
temperature, the backlight will turn off.
All the other functions are controlled by use of the
switch or jumpers as described in the previous section –
a brief description of each function is given here.
Heat/Cool:
The ERT20T T
heating applications. The operating mode can be
changed using the switch SW1 – if cooling mode is
selected, the PWM option is switched off automatically
Night Setback(NSB)
T
the best ways to manage heating energy in an
economical way
temperature reduction (setback) function which allows
you to automatically reduce or increase the set
temperature by 2 °C or 4 °C, depending on whether the
ERT20T T
The Setback function is activated by an external signal
(e.g. signal from an external time clock or timer). The
Setback feature will only operate if a connection is
made to the Setback terminal .
If the terminal state is HIGH (above 175V
temperature will be applied.
Pulse Width Modulation (PWM):
Heating systems can have a problem with overshoot
(rooms continue to be heated even after the set
temperature has been reached). The ERT20T T
this problem electronically using a method of control
called Pulse Width Modulation (PWM).
By continuously comparing the set temperature with
the actual temperature, the opening times for the
system valve actuators are regulated so that the set
temperature can be reached and regulated in a precise
and accurate way
The PWM function only works when the ERT20T T
set to operate in Heat mode.
V
The V
to avoid the control valve from sticking or seizing when
not being used for long periods (e.g. during the
summer). When enabled, the VP function will turn on
the thermostat output to operate the control valve for
a period of 5 minutes every week.
The VP function will still operate even if the room
temperature is higher than 35 °C, and regardless of
whether the ERT20T T
ERT20T T
also can be controlled by its master via Clock
terminal(communication),the external signal is 230V
constant voltage or pulse (this is called Communication
Mode).
For example,you can connect ERT20T with ER
Clock terminal,in this network,ERT50T T
and ERT20 is a slave.In this mode, the communication
between master and slave contains Heat/Cool+ Setback
2°C/4°C/off, the communication is not a simple voltage,
there are 6 kinds of commands, i.e. Heat+ setback off,
Heat + 4°C, Heat+2°C, Cool + setback off, Cool+4°C,
Cool+2°C, and the pulse width is different for the
different command. Even the setback is of
still can control slave (still has Heat/Cool command).
ENERGY TIP
One way to set and use your room thermostat is to find
the lowest temperature setting that you are
comfortable with, and then leave it set at this
temperature. Y
thermostat to a low temperature, (for example 17 °C)
and then increasing the setting by one degree each day
until you are comfortable with the room temperature -
you won’t have to adjust the thermostat further
adjustment above this setting will waste energy: a 1 °C
increase in temperature is equal to 3% of your heating
costs.
Maintenance
The ERT20T T
no special maintenance. Periodically
can be wiped clean using a dry cloth (please DO NOT
use solvents, polishes, detergents or abrasive cleaners,
as these can damage the thermostat).
There are no user serviceable parts within the unit; any
servicing or repairs should only be carried out by Salus
Controls or their appointed agents.
Should the ERT20T T
correctly
• The ERT20T T
• Heating system time switch or programmer
is switched on.
WARRANTY
Salus Controls warrants that this product will be free
from any defect in materials or workmanship, and shall
perform in accordance with its specification, for a period
of two years from the date of purchase. Salus Controls
sole liability for breach of this warranty will be (at its
option) to repair or replace the defective product.
Product Specification
Model: ERT20T T
T Electronic room thermostat designed for
underfloor heating applications.
Operation
Control Method:
1. PWM control (default)
2. On – Off control
T
T 5.0 ºC – 30.0 ºC
T ± 1.0 ºC
Environment
Operating T
Storage T
Salus Controls plc,
Salus House, Dodworth Business Park South,
Whinby Road, Dodworth, Barnsley S75 3SP
Sales Email: sales@salus-tech.com
T
Ttech@salus-tech.com
T
Model No:
4C
PWM
On Off
On/Off
2C
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