Evolution EVC-H Instruction Manual

Document No. NISM/EVC-H/01
Date NOV 2003

NITTAN (UK) LTD.

Hipley Street, Old Woking, Surrey, England, GU22 9LQ. UK

Tel: [phone] Fax: [phone] Web Site: www.nittan.co.uk E-mail: [e-mail]

EVC-H CONVENTIONAL HEAT DETECTOR

INSTRUCTION MANUAL

evolution

Quality System Certificate No. 041

Assessed to BS EN ISO 9001:2002

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evolution.....

The EVC-H Heat Detector forms part of a brand new range of fire detectors
from Nittan (UK) Ltd called

evolution.

The EVC-H is an elegantly designed, low profile detector which is
aesthetically pleasing, thus enabling it to blend unobtrusively into modern
working environments.

The EVC-H is compatible with other existing conventional fire detection
systems.

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CONTENTS:-

Section 1 - Introduction - Page 2
Section 2 - Operation - Page 2
Section 3 - Detector Models - Page 3
Section 4 - Base Models - Page 3
Section 5 - Installation - Page 3
Section 6 - Connections - Page 3

Section 7 - Maintenance &

Cleaning - Page 4
Section 8 - Specification - Page 5
Section 9 - EMC - Page 5
Section 10 - Dimensions - Page 5

Section 11 - Response

Characteristics - Page 6

Section 1 - INTRODUCTION

The EVC-H is an attractively styled, fast response, low
profile heat detector.

It has been designed to replace any previous Nittan heat
detector.

EVC-H features:

* Low profile, stylish appearance

* Different response grades available

* Non-polarised terminals

* Unauthorised head removal signal facility

* Low monitoring current

* Patented OMNIVIEWTM 360o LED alarm indicator

* Remote indicator output

* Compatible with STB-4, STB-4SD and STB-4SE
bases

Section 2 - OPERATION

The EVC-H range of heat detectors are non mechanical
and use a thermistor of low thermal mass as the sensing
element giving a fast response. Although these
detectors operate on a fixed temperature threshold only,
their fast response makes them generally suitable for

use where rate-of-rise detectors would be used.

Fig. 1. Block Diagram of EVC-H Detector Circuit

FIG. 1

RECTIFIER

AND

FILTER

OPERATION

INDICATOR

SWITCHING

UNIT

VOLTAGE

STABILISER

+ve
(3)

-ve
(1)

-ve
(6)

SENSING

THERMISTOR

INTERNAL

REFERENCE

COMPARATOR

UNIT

Rem. Ind. (5)

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the sensor is undertaken. At commissioning, the dust
cover should be removed and discarded.

NOTE: THE PLASTIC DUST COVER MUST BE
REMOVED FROM THE SENSOR IN ORDER FOR THE
SENSOR TO FUNCTION CORRECTLY.

Section 6 - CONNECTIONS

Connections are made to the detector base. The con­nections used depend on the type of base and the
functions required. See Section 4 'Base Models', to
identify the required type of base and functions sup­ported. See below Figures 2, 3 & 4 for wiring to the
detector's base:-

Section 3 - DETECTOR MODELS:

The EVC-H range of heat detectors are currently avail­able in two versions. Others can be made
available upon demand

i) EVC-H-A2
ii) EVC-H-C

These versions have three terminals for connection onto
the two wire zone circuit. The remaining terminal (5)
provides a switched current sink function which operates
when the detector goes into alarm condition, suitable for
the operation of auxiliary function such as a remote

indicator.

Section 4 - BASE MODELS

A variety of bases are available for use with the
EVC-H detectors. It is important to use the correct base
for each application. The available base models are:

i) STB-4 base: for standard use with EVC-H series heat
detector when auxiliary output not used.

ii) STB-4SD base: This is identical to the standard
STB-4 base, but also includes a schottky diode for head
removal fault monitoring. The schottky diode is used in
some fire systems to ensure power is
maintained, in the event of an unauthorised detector
head removal, to other detectors further on the zone.

iii) STB-4SE base: Similar to STB-4 base, except
deeper.

iv) STB-4SE-24VR base: Relay contact base.

Section 5 - INSTALLATION

In normal use, the EVC-H detector will be installed at
ceiling level. Pass field wiring through cable hole in
centre of base from rear of base. Offer up and affix
base to the ceiling or conduit fitting with screws via the
base mounting holes. Connect field wiring to base
terminals as detailed in below section 'Connections',
making sure that wiring will not obstruct fitting of detec­tor head. Fit detector head by inserting into base and
turning clockwise until notch in detector rim aligns with
base locking screw. The OMNIVIEWTM indicator per­mits visibility from any angle.

Fit the plastic dust cover supplied over the sensor to
keep out dust etc, until the system is commissioned. If
the dust cover is not fitted and the environment is
slightly dusty, such as when building work is being
completed, for example, problems of false alarms are
likely to occur after commissioning unless cleaning of

STB-4-SD base

STB-4 base

STB-4 and STB-4-SE bases

E.O.L

3

1

6

1

6

1

6

3

5

5

Max. current through
(5)= : 20 mA (total)

+

R.I.L

+

3

If +ve supply derived from zone,
then RIL must be LED type

_

_

Max. current through
(5)= : 20 mA (total)

+

_

+

_

E.O.L

E.O.L

FIG. 2

FIG. 3

FIG. 4

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Section 7 - MAINTENANCE AND CLEANING

Maintenance:

The EVC-H detector is a high quality product engineered
for reliability. In order to obtain optimum performance,
periodic maintenance is required. If proper preventative
maintenance is not carried out, there is a likelihood of
malfunction, including false alarms.

Servicing:

Servicing of the system should be carried out in accord­ance with the requirements of BS 5839 Part 1, Fire
Detection and Alarm Systems for Buildings: Code of
Practice for System Design, Installation and Servicing.

The maintenance procedures described below, should
be conducted with the following frequency:

One month after installation: Routine Inspection

and every 3 months

thereafter.
Every 6 months: Operational Test.
Every 12 months: Functional Test and

Cleaning.
All above frequencies of maintenance are dependent on

ambient conditions.

Routine Inspection:
i) Ensure that the detector head is secure and undam-

aged.
ii) Check that the heat entry apertures are in no way

obstructed.
iii) Ensure that the surface of the detector’s outer cover

is clean. If there are deposits due to the presence of oil
vapour, dust etc, then the detector should be cleaned in
accordance with the cleaning instructions detailed later
in this manual. It may be advisable to ensure that such
cleaning is conducted regularly in future.

iv) Ensure that no equipment which may generate
excessive heat has been installed in the vicinity of the
detector since the last routine inspection. If such
equipment has been installed, then you should notify
the Safety Officer or other competent authority that its
presence may cause false alarms.

Operational Test

The purpose of the Operational Test is to confirm the
detector’s correct operation in response to a heat
condition.

i) Take any necessary precautions at the control panel
to limit the sounding of the alarm sounders/bells and

any fire service summoning device.
ii) Test the detector with heat from a warm air gun

designed for heat detector testing (e.g. 'No Climb - Solo'
heat sensor tester). Check that the detector gives an
alarm condition within 10-20 seconds depending upon
the detector grade and the applied air temperature.
Check that the LED indicator on the detector illumi­nates.

N.B. Hot air blowers sold for paint stripping, solder­ing pipes etc, generate sufficient heat to damage the
detector and should not be used for testing heat
detectors.

iii) After the detector has given the alarm condition,

reset the detector from the control. It may be neces­sary to allow some short time to elapse before resetting
the detector, to allow any residual heat from the test to

disperse.

iv) Before proceeding to the next detector, ensure that
the detector just tested does not re-operate due to the

presence of residual heat.

Functional Test:

The Functional Test checks the detectors operation.
These detectors may be returned to our factory for
Functional Testing.

Cleaning:
Note: The sensor head should NOT be disassembled.

i) Carefuly remove the heat detector from its base.
ii) Use a soft, lint-free cloth, moistened with alcohol for

sticky deposits, to clean the plastic cover.

iii) Using a soft bristle brush (e.g. an artists paintbrush)
carefully brush between the vanes and thermistor in a
linear motion away from the apertures on the plastic

case.

iv) Ensure that no debris is left on or around the ther­mistor once cleaning is complete.

v) If the unit needs further cleaning or is damaged or
corroded, please return the complete detector to Nittan
(UK) Ltd. for service.

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Section 8 - SPECIFICATIONS

Model References: EVC-H-A2, EVC-H-C
Computer References: EVC-H-A2 - F04N82501

EVC-H-C - F04N82503

Sensing Element
& Principle: Thermistor of low thermal

mass.

Supply Voltage: 24V dc nominal (range 16

to 32V)

Voltage Ripple: 20% maximum
Alarm Voltage: 6V d.c. in series with 375R

between +(terminal 3) and

-(terminals 1,6) at 25oC

Monitoring Current: 30 µA maximum at 24Vd.c.
Alarm Current: 50 mA maximum at

25 deg. C

Charging Time: 20 seconds

Ambient Temperature
Range: EVC-H-A2 -10 oC to +55 oC

EVC-H-C -10 oC to +80 oC

IP Rating: 41

Section 9 - EMC

Installation

The installation shall be in accordance with the
regulations either of the approval body for an approved
system, or otherwise, to the national code of practice/
regulations for the installation of the fire alarm system,
e.g. BS 5839 part 1.

Electromagnetic Compatibility (EMC)

On a site where there is an unusually high level of
potential electrical interference, e.g. where heavy
currents are being switched or where high levels of R.F.
are prevalent, then care must be taken in the type and
routing of cables. Particular care should be given to
the separation of zone wiring from the cable carrying the
interference.

15mm

43mm

∅104mm

Section 10 - DIMENSIONS

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Section 11 - RESPONSE CHARACTERISTIC GRAPHS

EVC-H Rate of Rise Response (Degree C/Min)

0

10

20

30

40

50

60

70

80

90

100

0 5 10 15 20 25 30 35 40 45 50

Response Time (Minutes)

Temperature

A2
C
1deg/m
3deg/m
5deg/m
10deg/m
20deg/m
L Limit Others
U Limit Others

20 10 5 3

1