Nittan NHD-G series User manual

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NISM/NHD/03
NHD-G SERIES
HEAT DETECTOR
INSTRUCTION MANUAL
MARCH 2001
15
OF 03
CONTENTS
Section 1 - Introduction - Page 1
Section 2 - Operation - Page 1
Section 3 - Detector Models - Page 2
Section 4 - Base Models - Page 2
Section 5 - Installation - Page 2
Section 6 - Wiring - Page 2
Section 7 - Maintenance
Cleaning - Page 3
Section 8 - Specification - Page 4
SECTION 9 - EMC - Page 4
Section 10 - DIMENSIONS - Page 4
Section 11 - Accessories - Page 5
Section 12 - Response
Characteristics - Page 5
SECTION 1 - INTRODUCTION
The NHD-G range of attractively tyled, fa t re-
pon e, low profile heat detector .
They have been de igned, in mo t ca e , to replace
our 2SA-70T-LS, TCA-70-LS AND TCA-60-LS
Feature :
* Low profile, tyli h appearance
* Four different re pon e grade
* Non-polari ed terminal
* Head removal ignal facility
* Low monitoring current
* Integral LED alarm indicator
* Remote indicator output
* Ea y maintenance
SECTION 2 - OPERATION
The NHD-G range of heat detector are non mechani-
cal and u e a thermi tor of low thermal ma a the
en ing element giving a fa t re pon e. Although
the e detector operate on a fixed temperature
thre hold only, their fa t re pon e make them
generally uitable for u e where rate-of-ri e detector
would be u ed.
Fig. 1. B ock Diagram of NHD-G Detector Circuit
RECTIFIER
AND
FILTER
OPERATION
INDICATOR
SWITCHING
UNIT
VOLTAGE
STABILISER
P+
L
CI
CII
SENSING
THERMISTOR
INTERNAL
REFER-
ENCE
COMPARITOR
UNIT
FIG. 1

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NISM/NHD/03
NHD-G SERIES
HEAT DETECTOR
INSTRUCTION MANUAL
MARCH 2001
25
OF 03
SECTION 3 - DETECTOR MODELS
The NHD-G range of heat detector are available in
four ver ion .
i) NHD-G1 (58 deg. C) with 4 terminal . BS 5445 /
EN54 Grade 1. (Part 5)
ii) NHD-G2 (66 deg. C) with 4 terminal . BS 5445 /
EN54 Grade 2. (Part 5)
iii) NHD-G3 (74 deg. C) with 4 terminal . BS 5445 /
EN54 Grade 3. (Part 5)
iv) NHD-GH1 (80 deg.C)with 4 terminal . BS 5445 /
EN54 Range 1. (Part 8)
The e ver ion have three terminal for connection
onto the two wire zone circuit. The remaining
terminal(P+) provide a witched current ink function
which operate when the detector goe into alarm
condition, uitable for the operation of auxilliary func-
tion uch a a remote indicator.
SECTION 4 - BASE MODELS
A variety of ba e are available for u e with the NHD-G
detector . It i important to u e the correct ba e for
each application. The regularly u ed ba e model are:
i) RB-3 Ba e for tandard u e with NHD-G erie heat
detector when auxiliary output not u ed.
ii) RB-3R Ba e having erie re i tor fitted, for u e
with NHD-G 4T detector when auxiliary function not
u ed. Serie re i tor increa e overall re i tance of
detector/ba e. Thi hould not be u ed to provide a
volt drop for powering a remote indicator if the control
panel need to  ee the erie re i tor in order to
di tingui h between a hort circuit fault and a fire alarm
condition. Thi i becau e the pre ence of a hort
circuit fault in the wiring to the remote indicator will
effectively hort out the re i tor.Three tandard re i tor
value are available: 220 ohm, 470 ohm and 680 ohm.
iii) RB-6 Ba e having 6 terminal , for u e with the
NHD-G 4T detector when auxiliary output i required.
Thi ba e i normally u ed when a remote indicator i
required. If the control panel need to  ee a higher
re i tance than the detector alone provide , in order to
di tingui h between a hort circuit fault and a fire
alarm, then a erie re i tor will need to be incorpo-
rated in thi ba e.
iv) Other ba e including tho e that provide continuity
of the zone wiring in the event of a detector head
removal, four-wire ba e etc. Refer to wiring in truc-
tion for tho e ba e for detail .
RB-6 base
RB-6 base
RB-3 base
E.O.L
L
C
C
C
C
C
C
L
P+
P+
Max. current through
P+= : 100 mA (tota )
+
R.I.L
+
R.I.L
+
L
L
If +ve supp y derived from L,
then RIL must be LED type
+
_
_
_
C
Max. current through
P+= : 100 mA (tota )
+
L
_
C
SECTION 5 - INSTALLATION
In normal u e, the NHD-G detector will be in talled at
ceiling level. Pa field wiring through cable hole in
centre of ba e from rear of ba e. Offer up and affix
ba e to the ceiling or conduit fitting with crew via the
ba e mounting hole . Con ider vi ibility and orienta-
tion of detector integral alarm indicator when mounting
ba e. Connect field wiring to ba e terminal a
detailed in below ection 'Wiring', making ure that
wiring will not ob truct fitting of detector head. Fit
detector head by in erting into ba e and turning
clockwi e until notch in detector rim align with ba e
locking crew.
SECTION 6 - WIRING
Connection are made to the detector ba e. The
connection u ed depend on the type of ba e and the
function required. See Section 4 Ba e Model , to
identify the required type of ba e and function up-
ported. See below Figure 2,3, & 4 for wiring to the
detector' ba e:-
+
L
_
C
E.O.L
E.O.L
FIG. 2
FIG. 3
FIG. 4

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NISM/NHD/03
NHD-G SERIES
HEAT DETECTOR
INSTRUCTION MANUAL
MARCH 2001
35
OF 03
SECTION 7 - MAINTENANCE AND CLEANING
The NHD-G detector i a high quality product engineered
for reliability and to obtain optimum performance,
periodic maintenance i required. If proper preventative
maintenance i not carried out, there i a likelihood of
malfunction, including fal e alarm . Servicing of the
y tem hould be carried out in accordance with BS
5839 Part 1, Fire Detection and Alarm Sy tem for
Building : Code of Practice for Sy tem De ign, In talla-
tion and Servicing.
The maintenance procedure de cribed below, hould
be conducted with the
following frequency:
One month after installation: Routine In pection
and every 3 month
Every 6 months: Operational Te t
Every 12 months: Functional Te t and
depending on
ambient condition ,
Cleaning
Routine Inspection
i) En ure that the detector head i ecure and undam-
aged.
ii) Check that the thermi tor entry aperture are in no
way ob tructed.
iii) En ure that the urface of the detector outer cover
i clean. If there are depo it due to the pre ence of oil
vapour, du t etc, then the detector hould be cleaned in
accordance with the cleaning in truction detailed later
in thi manual. It may be advi able to en ure that uch
cleaning i conducted regularly in future.
iv) En ure that no equipment which may generate
exce ive heat, ha been in talled in the vicinity of the
detector ince the la t routine in pection. If uch
equipment ha been in talled, then you hould notify
the Safety Officer or other competent authority that it
pre ence may cau e fal e alarm .
Operational Test
The purpo e of the Operational Te t i to confirm the
detector correct operation in re pon e to a heat condi-
tion.
i) Take any nece ary precaution at the control panel
to limit the ounding of the alarm .
ii) Te t the detector with heat from a warm air gun
de igned for heat detector te ting or a imilar device
uch a a hair dryer. Check that the detector give an
alarm condition within 10-20 econd depending upon
the detector grade and the applied air temperature.
Check that the LED indicator on the detector illumi-
nate .
N.B Hot air blowers sold for paint stipping, soldering
pipes etc, generate sufficient heat to damage the
detector and should not be used for testing heat
detectors.
iii) After the detector ha given the alarm condition,
re et thedetector from the control. It may be nece ary
to allow ome hort time to elap e before re etting the
detector to allow any re idual heat from the te t, to
di per e.
iv) Before proceeding to the next detector, en ure that
the detector ju t te ted, doe not reoperate due to the
pre ence of re idual heat.
Functional Test
The Functional Te t check the detector operation.
The Functional Te t can only be carried out with the
NID-ET3 Electronic Te ter with uitable adapter. How-
ever, the e detector may, be returned to our factory for
Functional Te ting.
Detail of the Functional Te t method are given in the
In truction Manual for NID-ET3, ref. NISM/ET35/01A.
Cleaning
i) Remove the heat detector from it ba e.
ii) U ing a oft lint-free cloth, moi tened with alcohol
for ticky depo ite , to clean the pla tic cover.
iii) U ing a oft bri tle bru h carefully bru h between
the vane and thermi tor in alinear motion away from the
pla tic cover.
iv) En ure that no debri i left on or around the ther-
mi tor once cleaning i complete.
v) When replacing the outer cover, make ure that the
led indicator locate properly in the hole in the outer
cover before pu hing the cover home otherwi e the led
will become damaged.

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NHD-G SERIES
HEAT DETECTOR
INSTRUCTION MANUAL
MARCH 2001
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Ultrasonic Cleaning
Thi method may be u ed to good effect for the re-
moval of contamination from the outer cover only.
However, care mu t be taken in election of the olvent
o a not to cau e damage to the pla tic. The olvent
upplier hould be con ulted a to it uitability.
Under no circum tance hould the fully a embled
detector be cleaned without di a embly a thi may
cau e damage to the pecial treatment of pecific
component within the detector (apart from the entrap-
ment of olvent in the cavitie of the detector with the
re ulting lo of olvent).
SECTION 8 - SPECIFICATION
Model References: NHD-G1,G2,G3 and GH1
Sensing Element
Principle Thermi tor of low thermal
ma .
Supply Voltage: 24V dc nominal (range 16 to
32V)
Voltage Ripple: 20% maximum
Alarm Voltage: 6V between L and C
terminal .
Monitoring Current: 30 µ amp maximum at 24V
Alarm Current: 65 milliamp maximum at 25
deg. C - ee note
Charging Current: 100 milliamp maximum
(power on)
Charging Time: 20 econd
Ambient Temperature
Range: -25 Deg.C. to +90 Deg.C..
Note The power supply to the detector should
limit the maximum current that the detector can
draw 65mA. If the current is not limited then the
detector may be
damaged.
SECTION 9 - EMC
INSTALLATION AND ELECTROMAGNETIC COM-
PATIBILITY (EMC.)
The in tallation hall be in accordance with the regula-
tion either of the approval body for an approved
y tem, or otherwi e, to the national code of practice/
regulation for the in tallation of the fire alarm y tem,
e.g. BS 5839 part 1.
ELECTROMAGNETIC COMPATIBILITY
On ite where there i an unu ually high level of poten-
tial electrical interference, e.g. where heavy current
are being withched or where high level of R.F. are
prevalent, then care mu t be taken in the type and
routing of cable . Particular care hould be given to
the eparation of zone wiring from the cable carrying
the interference.
SECTION 10 - DIMENSIONS
63mm
23mm
120mm

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NISM/NHD/03
NHD-G SERIES
HEAT DETECTOR
INSTRUCTION MANUAL
MARCH 2001
55
OF 03
SECTION 12 - RESPONSE CHARACTERISTIC GRAPHS
SECTION - 11 ACCESSORIES
The following acce orie are available for the NHD-G
detector:
NID-E4 Head Removal Tool for u e with exten ion
rod to extract detector from ceiling.
DP-2 Detector Protector, wire cage to protect from
knock and vandali m etc.
Variety of ba e including 4-wire, line continuity etc.
Variety of remote indicator 6 v, 24 v led type.

Document No. NISM/NHD/03
Date MARCH 2001
NHD-G SERIES
CONVENTIONAL HEAT
DETECTOR
INSTRUCTION MANUAL
LPCB REF: 041a/01 (NHD-G1)
LPCB REF: 041a/02 (NHD-G2)
LPCB REF: 041a/03 (NHD-G3)
LPCB REF: 041b/01 (NHD-GH1)
NITTAN (UK) LTD.
Hip ey Street,
O d Woking,
Surrey, Eng and,
GU22 9LQ United Kingdom
Te : [phone]
Fax: [phone]
Web Site: www.nittan.co.uk
e-mai : sa [email protected]
Quality System Certificate No. 041
Assessed to BS EN ISO 9002