SEELEY INTERNATIONAL
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51
TECHNICAL BULLETIN:
ICON CONTROL BOX FAN SPEED LED BEHAVIOUR
Subject: Icon Control Box Fan Speed LED Behaviour
Region: Australia
Author: Technical Support 1300 650 399
Date: 12/09/2014
TECHNICAL BULLETIN
ICON Control Box Fan Speed LED
Behaviour
To accurately diagnose Icon products, we
strongly recommend that Service Technicians
use a CPMD compatible Wall controller and
a short test lead (Pt number 862873) at the
Cooler. This way all the functions of the cooler,
as well as the Motor diagnostic LED’s can
be observed in relation to the Wall control
commands.
IMPORTANT SAFETY:
When any side panels
are removed, always test EVAP coolers with
the pump disconnected or in ventilation mode,
as wet roof surfaces can create a safety
hazard! Also, care must always be taken when
working near or around moving parts.
The ICON fan speed LED behaves as
follows:
1. It glows solid green in normal operation.
2. The Fan Speed LED will extinguish if
the motor rotates less than 30% of set
speed*, and the motor will stop within
approximately 30 seconds at speed 10
(longer at lower speeds), or if the fan
remains stationary for 30 seconds after it
was supposed to start.
Fan under speed is usually associated with
the following.
• Shorting between phase windings inside the motor
• Worn bearings causing the motor to start to seize
up
3. If motor rotates 20% faster than set
speed* this LED will continually flash, and
the motor will stop within approximately
30 seconds (sooner at higher speeds).
4. If the speed increases to 30% above the
set speed* the LED will continue to flash
and the motor will stop immediately
Fan over-speed is usually associated with
restricted (reduced) airflows:
• Fan installed backwards (motor may have recently
been changed)
• Weather damper jammed or not opening fully
• Undersized or squashed ductwork
• Registers (grilles, diffusers) not open
• Large extraction fans causing negative back
pressure
•
Voltage outside of specifications (less than 207volt
or more than 253volt).
* ‘set speed’ –
Is the fan/motor speed as
selected by the operator or by the thermostat
in the Wall Control. Each motor speed has
a specified value of input power assigned
to it (factory set). Regardless of installation
conditions the input power to the motor is
held constant at that specific value. Data from
sensors in the motor is converted to RPM in
the electronic module. The speed at each of
the 10 settings is allowed to vary +/- 20%. As
soon as the motor RPM moves outside those
limits (for any of the above listed causes) a
fault mode is initiated and the LED behaves as
stated above.
Seeley International has a policy of
continuous improvement in all areas. This
is one of the many product improvements
and enhancements that we are making
to our large range of cooling and heating
products.
