Crowcon Flamgard-Plus Инструкции - Страница 4

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c. Remove the amplifier.

d. Disconnect the 3 sensor wires from the terminal board (terminals 4, 5 & 6).

e. Unscrew the complete 96HD sensor housing from the junction box.

Note: If a spare 96HD sensor housing complete with new sensor is

available ignore steps f to k and return the old 96HD to Crowcon or an

approved service centre for repair.

f. Open the 96HD sensor housing by removing the four Allen head screws

from the Top Cap with a 3mm Allen key.

g. Remove the sensor from the Top Cap PCB. Flammable sensors have an

extra black sleeve which may be separate from the sensor. This is normal

and the sleeve may be re-used.

h. Fit the replacement sensor checking the part number is correct. This part

number is labelled on the main body of the detector.

i. Inspect the gaskets and replace if necessary.

j. The sinter assembly will only need to be replaced if it has become blocked

by dust or oil. Such blockage causes the response time of the detector to

be slow and may affect sensitivity. To remove the sinter a removal tool (Part

# M01614) is required. Loctite No 243 must be used on the sinter

assembly threads to maintain certification.

TOP CAP AND SENSOR PCB

NEOPRENE GASKET 1

(Part No. M04452)

GASKET 2

(Part No. M04128)

SINTER ASSEMBLY

(Part No. S01781)

SINTER

Diagram 4: 96HD assembly

k. Re-assemble the 96HD housing taking time to ensure that the 3 mm Allen

head screws are securely fixed into position.

l. Fit the 96HD sensor housing to the junction box ensuring that the colour

coded wires are terminated correctly.

m. Replace amplifier ensuring the captive screws are fastened securely.

n. Switch on power.

o. Using a DVM measure the voltage across Test Points 'A' and adjust Set

Bridge Volts (Pot A) until the DVM reads correctly (see Table 3 for complete

list).

p. Using a DVM measure the voltage across Test Points 'B' and adjust Set

Balance (Pot B) until the DVM reads 0 mV.

4 OFF M4 X 12 mm

ALLEN HEAD SCREWS

PELLISTOR

SLEEVE

MAIN BODY

q. Close the junction box remembering to fasten the tamper proof grub

screw into position.

r. Follow the Commissioning Procedure given in 4.1.

Sensor

Element

Test point 'A'

Part no.

voltage (mV)

S01-637/A

VQ21T

300P

VQ8

VQ16

VQ22

VQ25

VQ41

VQ1

Table 3: Voltages of replacement sensors at test point 'A'

4.4 Changing Alarm Levels (Relay Version Only)

WARNING

This work should be carried out by Crowcon or an approved service

centre unless suitable training has been received. Before attempting

to change alarm levels ensure the detector is in fresh air and no

flammable gas is present.

As standard the AL1 and AL2 alarm levels are factory set at 20% LEL and

40% LEL respectively. To change either alarm level:

a. Switch off and isolate power to the detector requiring attention.

b. Open the junction box of the detector by loosening the tamper proof grub

screw and removing the lid by rotating it anti-clockwise.

c. Remove the amplifier from the terminal board

d. Ensure that the 'INHIBIT' link is set to 'N'.

e. Re-fit the amplifier to the terminal board ensuring that all screws have

been secured correctly.

Apply power to the detector and allow the detector to stabilise.

g. Place the end of 'CRO-Mag' over the 'MENU' pad. The decimal point

above the word 'ZERO' will illuminate, the Status LED will flash green and

the display backlight will illuminate.

h. With no flammable gas present at the detector, place the end of the

'CRO-Mag' key over the 'UP' or 'DOWN' arrow pads to make the display

read the desired alarm level.

Using a long instrument screwdriver, turn the relevant ALARM SET pot

mounted on the terminal board (see Diagrams 1 & 2) to adjust the alarm

level. Tripping of the ALARM 1 level relay is confirmed by the status LED

turning a steady red. Tripping of the ALARM 2 level relay is confirmed by

the Status LED flashing red.

Once the alarm level has been set, place end of 'CRO-Mag' over the 'UP'

or 'DOWN' arrow pads and reset the display to read zero.

k. Place the end of the 'CRO-Mag' over the 'MENU' pad to return the

detector to normal operation, ie. No decimal points displayed, backlight

off and the Status LED indicating steady green.

Check that the detector operates correctly by applying test gas as

necessary.

m. Switch off and isolate power to the detector.

n. Reset jumpers which may have been changed in step 'd' above.

o. Replace the amplifier and close the junction box, ensuring that all screws

have been re-fitted correctly.

p. Apply power to the detector and allow to stabilise before checking correct

operation.

q. Re-calibrate if necessary as per section 4.1.

Comment

310

Poison resistant

310

Poison resistant alternative

350

Lead resistant

350

Early model

170

Low power

310

For Halogens

310

Ammonia or aviation fuel

310

Early model