NASA MARINE Exhaust Gas Temperature Indicator with Alarm Manual

DESIGNED AND
MANUFACTURED
IN ENGLAND

EX-1

INSTALLATION AND

USER INSTRUCTIONS

MARINE INSTRUMENTS

RoHS

2002/95/EC

NASA MARINE Ltd.

BOULTON ROAD

STEVENAGE

HERTS SG1 4QG

ENGLAND

INTRODUCTION.

It is common practice to inject cooling water into marine engine
exhaust systems. This cooling reduces the exhaust gas temperature
to a level where rubber and polymer exhaust components can be
used.

Such "wet exhaust" systems perform reliably and have a good life
expectancy as long as the cooling water is always present. A failure of
cooling water, even for a short period, can lead to catastrophic
damage of the exhaust system components which, in turn, can lead to
fires, leaks of toxic gasses and reduced exhaust life expectancy.

A cooling water failure can be caused by a temporary blockage of the
raw water inlet by a plastic bag or other debris or it could result from a
burst pipe or poorly performing water pump. Either way an engine
temperature gauge will not give adequate warning. The temperature of
the engine block, full of water, will rise very slowly whilst the exhaust
gas temperature will rise from a few tens of degrees centigrade to a
few hundred degrees centigrade in a matter of seconds.

To give advanced warning of cooling water problems, either
restrictions or complete failure, requires an exhaust temperature
sensor. Some sensors measure the temperature of the outside of the
exhaust hose. Unfortunately, as rubber exhaust hoses conduct heat
poorly, by the time a warning is given the internal temperature may
have already exceeded the manufactures recommended maximum. A
further problem with such a device is that the user has no way of
knowing if it will actually work when needed.

The EX-1 measures the exhaust gas temperature directly and
displays it in degrees centigrade or fahrenheit. Once the normal
working temperature has been established a maximum temperature, a
few degrees higher, can be programmed into the EX-1 which will then
sound an audible alarm if that temperature is exceeded.

Even a small rise in temperature can indicate a potential problem such
as a minor blockage, leak or failing pump which can be corrected
before a complete failure occurs.

1

INSTALLING THE SENSOR.

Select a position on the rubber exhaust hose about 150mm back from
the water injection point and drill a 5mm hole in the top taking care to
avoid the steel reinforcing wire.

Push the tip of the sensor probe through the hole and use the high
temperature tie wraps to secure the red mounting bracket. Tighten the
tie wraps until the sensor is secure but do not over tighten. To prevent
excessive stress on the sensor, the cable should be clipped to one of
the large tie wraps using a small tie wrap as shown in fig. 1.

Connect the 5 meter cable into the terminal block on the sensor
junction board. Use a small tie wrap to retain the cable to the board
then clip the box around the assembly. Run the 5 meter cable to the
display. You can shorten or extend this cable as required.

INSTALLING THE DISPLAY.

The display unit is not watertight and must be mounted in a dry area.
Select a convenient position and screw it to a flat bulkhead. The wires
can be arranged to pass directly through the bulkhead or exit through
the slot at the bottom of the display.

Connect the wires into the four way junction box as shown in fig. 2.
The blue and brown wires go to the sensor probe, the black and red
wires go to the 12 volt supply. (black negative and red positive) For
convenience the supply can be taken from the engine switch. It is
recommended that a 1 amp fuse is fitted in the positive line

2

USING THE EX-1.

When power is first connected to the EX-1 it will display the
temperature of the tip of the stainless steel sensor in degrees
centigrade, also the display backlight will illuminate for a period of two
minutes.

Pressing any key will turn the backlight on for a further two minutes.

Pressing both keys simultaneously will change the scale from
Centigrade to Fahrenheit and vice versa.

On pressing the SET key the unit will display the alarm threshold
temperature together with the word SET.(The factory default setting is
85 degrees centigrade.)
Pressing the TEMP key will return to the normal monitoring mode.
Alternatively, if the key is not pressed, the unit will return to its normal
monitoring mode after a period of thirty seconds.

If the tip of the sensor exceeds the alarm threshold temperature then
the word HOT will appear on the display, the alarm will sound and the
back light will flash rapidly.
If the sensor temperature subsequently falls below the threshold
temperature then the alarm will clear and the unit will return to its
normal mode. Should the alarm condition continue then the alarm can
be cancelled by pressing either key. This will return the unit to
monitoring mode. However, if the temperature of the sensor fails to
fall below the threshold temperature after two minutes the alarm will
sound again.

3

CHANGING THE ALARM THRESHOLD TEMPERATURE.

It is normal practice to run up the engine to full load and note the
maximum exhausted temperature. The alarm threshold temperature
can then be set a few degrees (Usually about 10 degrees centigrade)
higher. It is important however that the threshold temperature does
not exceed the manufacturer's recommended limits for any part of the
exhaust system.

To adjust the alarm threshold temperature press SET, to display the
current alarm threshold, then depress the SET key for a period of
about ten seconds until the word CHAnge is displayed. The SET and
TEMP keys can now be used to increment or decrement the
threshold. When the desired alarm threshold has been selected wait
thirty seconds and the display will then revert to normal operation.

ERROR MESSAGES.

If a sensor wire becomes disconnected the back light will flash and
the word OPEN will scroll across the display to indicate that the
sensor is open circuit. If the sensor wires become shorted together
then the backlight will flash and the word SHORT will scroll across the
display. If either of these messages occur then check the sensor
wiring.

EX-1 SPECIFICATION.

Voltage 8 to 15 volts DC.
Current < 1.5 mA.
Temperature range -30 to +170 degrees Centigrade.
Threshold range -30 to +170 degrees Centigrade.
( -22 to +338 degrees Fahrenheit.)

4

IMPORTANT READ THIS BEFORE

UNPACKING INSTRUMENT

Prior to unpacking this instrument read and fully understand the installation instructions.
Only proceed with the installation if you are competent to do so. Nasa Marine Ltd. will
not accept any responsibility for injury or damage caused by, during or as a result of
the installation of this product. Any piece of equipment can fail due to a number of
causes. Do not install this equipment if it is the only source of information and its failure
could result in injury or death. Instead return the instrument to your retailer for full credit.
Remember this equipment is an aid to navigation and not a substitute for proper
seamanship. This instrument is used at your own risk, use it prudently and check its
operation from time to time against other data. Inspect the installation from time to time
and seek advice if any part thereof is not fully seaworthy.

LIMITED WARRANTY

Nasa Marine Ltd. warrants this instrument to be substantially free of defects in both
materials and workmanship for a period of one year from the date of purchase.
Nasa Marine Ltd. will at its discretion repair or replace any components which fail in
normal use within the warranty period. Such repairs or replacements will be made at
no charge to the customer for parts and labour. The customer is however responsible
for transport costs. This warranty excludes failures resulting from abuse, misuse,
accident or unauthorised modifications or repairs. In no event shall Nasa Marine Ltd.
be liable for incidental, special, indirect or consequential damages, whether resulting
from the use, misuse, the inability to correctly use the instrument or from defects in
the instrument. If any of the above terms are unacceptable to you then return the
instrument unopened and unused to your retailer for full credit.

Name

Address

Dealer Name

Address

Date of Purchase

Proof of purchase may be required for warranty claims.

Boulton Road, Stevenage, Herts SG1 4QG England

Declaration of Conformity

NASA Marine Ltd declare this product is in compliance with the essential requirements of
R&TTE directive 1995/5/EC.
The original Declaration of Conformity certificate can be requested at [e-mail]
THIS PRODUCT IS INTENDED FOR USE ONLY ON NON SOLAS VESSELS

Nasa Marine Ltd.