Nuaire Thyristor Controlled Electric Heater User Manual

NALTCH

Thyristor Controlled Electric Heater

Installation Manual

1.0 SAFETY INFORMATION

• The provision of the electrical supply and the connection of the unit to the mains must be

carried out by a qualified electrician.

• Isolate from power supply before removing any covers. During installation / maintenance ensure

all covers are fitted before switching on the mains supply.

• All-pole disconnection from the mains as shown in the wiring diagram must be incorporated

within the fixed wiring and shall have a minimum contact separation of 3mm in accordance with
latest edition of the wiring regulations.

• This unit must be earthed.

• Ducting must be securely fixed with screws to the spigot to prevent access to live parts. Duct

runs terminating close to the fan must be adequately protected by suitable guards.

• If the supply cord is damaged, it must be replaced by the manufacturer, its service agent or

similarly qualified persons in order to avoid a hazard.

• This appliance should not be used by children or persons with reduced physical, sensory or

mental capabilities or lack of experience and knowledge, unless they have been given supervision
or instruction concerning the safe use of the appliance by a person responsible for their safety.
Children shall not play with the appliance. Cleaning and user maintenance shall not be carried
out by children.

1.1 Symbols

GENERAL WARNING

Signifies a general warning regarding hazard specified by supplementary information.

ELECTRIC SHOCK
This unit must be completely electrically isolated before any panels are removed. Check
mains supply and control connections.

REFER TO INSTRUCTION MANUAL
Read and understand the installation and maintenance manual before installing,
operating or maintaining this product.

1.2 Important Information

This manual contains important information on the safe and
appropriate assembly, transport, commissioning, operation,
maintenance, disassembly and simple troubleshooting of the product.

While the product has been manufactured according to the accepted
rules of current technology, there is still a danger of personal injury or
damage to equipment if the following general safety instructions and
the warnings contained in these instructions are not complied with.

•Read these instructions completely and thoroughly before

working with the product.

•Keep these instructions in a location where they are accessible

to all users at all times.

•Always include the operating instructions when you pass the

product on to third parties.

•When resetting the thermal cut-out, the heater may suddenly

switch on and element terminals, etc. will become live.

04. 08. 20. Document Number 671960Nuaire | Western Industrial Estate | Caerphilly | CF83 1NA | nuaire.co.uk

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1.3 Personal Protective Equipment

The following minimum Personal Protective Equipment (PPE) is
recommended when interacting with Nuaire product:

•Protective Steel Toed Shoes - when handling heavy objects.

•Full Finger Gloves (Marigold PU800 or equivalent) - when

handling sheet metal components.

•Semi Fingerless Gloves (Marigold PU3000 3DO or equivalent)

- when conducting light work on the unit requiring tactile
dexterity.

•Safety Glasses - when conducting any cleaning/cutting operation

or exchanging filters.

•Reusable Half Mask Respirators - when replacing filters which

have been in contact with normal room or environmental air.

Nuaire would always recommend a site specific risk assessment by a
competent person to determine if any additional PPE is required.

2.0 INTRODUCTION

Specifically designed to act as pre or re-heaters in small branch ducts
from a main AHU or on systems where the supply fan is controlled
from elsewhere. The thyristor controller is designed for use with heaters
up to and including 3kW single phase. There is no fan run-on timer so
the heater relies on a volt-free start signal and stays off until airflow is
detected by the combined DTFS airflow and temperature sensor.

Similar to other in-built thyristor controllers the unit has a temperature
set-point control on the front facia and indicator lamps to show the
status. The heater units come with a pre-wired high temperature
manual reset cut-out, a pre-wired duct mount combined DTFS airflow
proving and temperature sensor on a 1.8 metre fixed lead. This should
be mounted a minimum of 1M after the heater in the supply air duct.

Designed for simple installation into standard spiral ductwork systems
the heater operates automatically via the dictate of the temperature
setting and duct mounted temperature sensor to pulse the heater on
and off to maintain a constant supply air temperature. The temperature
set-point is adjustable 0-40 °C.

The unit is available in duties from 0.75 to 3kw.

2.1 Code Description:

NALTCH - 150

1. Range: Nuaire Thyristor Controlled Heater

2. Duct Size (Heater Power): 100 = 100mm Ø (0.75 kW)
150 = 150mm Ø (1.5 kW)
200 = 200mm Ø (2 kW)
250 = 250mm Ø (3 kW)

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3.0 MECHANICAL INSTALLATION

Installation must be completed by competent persons, in accordance
with good industry practice and should conform to all governing and
statutory bodies i.e. IEE, CIBSE, etc.

•Unpack the heater taking care to ensure items and paperwork are

removed from the centre of the heater duct.

•The terminal box may also contain wiring instructions. If you are

only installing the heater in the air duct, leave these instructions
for the electrician!

NALTCHInstallation Manual

•The heater can be installed into an ISO standard spiral duct

run, with either horizontal or vertical flow. With vertical ducts
consideration must be given to items in the run above the heater
which could be damaged by heat rising when the fan is switched
off. All heaters should be kept away from plastic conduits or
materials easily damaged by heat. Allow for casing temperature of
100°C (ideal minimum air velocity = 2m/s).

•These heaters must not be installed outside unprotected or in

areas that are washed down!

•To install the heater, measure between the swaged rings and cut

the spiral to suit. Use high temperature sealant and pop rivets to
fix. Do not use flexible connectors directly onto the heater. The
best position for the terminal box is on the side of a horizontal
duct. Ensure access to the terminal box is possible! Make sure
lagging etc. does not cover the terminal box.

•A combined temperature and airflow sensor will be found attached

to a coiled lead. This should be mounted in the duct 1.5 to 2m
downstream from the heater where the sensor cannot be damaged
by heat. A 20mm holesaw and 2 PK fixing screws will be required.

•The sensor has an Airflow direction arrow and will only

operate if installed with the arrow pointing in the direction of
airflow.

4.0 ELECTRICAL INSTALLATION

All wiring must be carried out by a qualified electrician in compliance
with the latest regulations.

These units are internally pre-wired and require only a suitable supply
feed connection to operate (see rating label). See wiring diagram for
connection details.

4.1 Wiring Diagram

All wiring must be carried out by a qualified electrician in compliance
with the latest regulations.

These units are internally pre-wired and require only a suitable supply
feed connection to operate (see rating label).

Wiring Diagram

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BLACK
WHITE
GREEN
BLUE
YELLOW

ON / OFF CORR TEMP AIR FLOW

Temp Control

F1A

HEATER

SUPPLY

NEUTRAL

NEUTRAL

0 SIG V

SUPPLY

HEATER

LIVE

LIVE

OVERTEMP

CUT-OUT

BROWN

MANUAL RESET

RESET

BUTTON

REMOTE VOLT-FREE STATUS

CLOSED = HEALTHY

OPEN = HEATER TRIPPED

GREEN / YELLOW

EARTH BOLT

BLUE

ELEMENT

COMBINED AIRFLOW &
TEMPERATURE SENSOR

2M LEAD

E

L

N

FUSED 230V SUPPLY

FROM LOCAL

ISOLATOR

04. 08. 20. Document Number 671960Nuaire | Western Industrial Estate | Caerphilly | CF83 1NA | nuaire.co.uk

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