JEM Glaciator X-Stream User Manual page 11

HEAVY FOG GLACIATOR
REFRIGERATION SYSTEM CONTROL
The performance of the refrigeration system in the Heavy Fog Glaciator is
the key to its heavy fog generating capability. The system is under the
complete control of the main microprocessor which also co-ordinates all the
other activities within the machine.
Four system temperatures are measured by the control system and are used
to regulate the flow of refrigerant via the PWM expansion valve. Replacing
the normal thermo-mechanical expansion valve with an electronically
controlled valve brings the following benefits:
Faster response to load changes
Improved control when on light loads
No adjustments required
Greater tolerance to changes in
Improved compressor starting when hot
Power saving idle mode
When the refrigeration system is switched off using the ICE switch on the
control panel it can only be started by setting the switch to ON. There will be
a delay of 10 to 30 seconds while the system pressures equalise, followed
by the motor starting. During the motor start cycle, the heaters are switched
off to reduce the peak current draw.
If the ICE switch is ON, but the compressor is not running, the system is in
power save mode. It will restart when the smoke system is fired (any signal
source) or when the ice switch is cycled. The starting delay will depend on
the current evaporator temperature, but will not prevent immediate
production of fog at full output.
If the machine is not fired, the evaporator temperature will drop to -25°C or
lower and a timer will start. When the unit has been at this temperature
(without being fired) for approximately 20 minutes, the system will shut down
and enter the power saving mode. Power save mode will continue until the
machine is fired, or the evaporator temperature reaches -4
To check the status of the refrigeration system at any time, use the ICE
menu on the right hand display panel. The left hand panel will now display
the name of the value, while the right hand display will show the
temperature. Use the scroll keys on the right hand display to move through
the available values.
12
gas charge
°C.
USER
GUIDE
To store the new value into non-volatile memory, the enter key must be
pressed before moving on to another menu or leaving the edit mode.
When not in edit mode, the display will show information appropriate to the
current operating mode. To do this, the display will alternate between two
messages. The duration of the first message is typically 1 second, whilst the
second message will be visible for 2 seconds. Some messages are
compounded together to form one message, eg FLu/Lo indicating low fluid in
the fluid container.
As an example, when the STANDBY switch on the control panel is set to
OFF (0), the display will alternate between FOG and OFF. For more
information about the messages to expect, see the sections covering the
different control functions on the machine, eg 'THE TIMER'. The section
entitled 'DISPLAY MESSAGES' contains a complete list of the messages
and the circumstances under which they are displayed.
The menus available on each display and the functions they perform are as
follows:
Fog Display
Fog
Sets the current Fog output level in the range 0 to 20.
Ton
Sets the ON time of the Timer in the range 0 to 90 (seconds).
ToF
Sets the OFF time of the Timer in the range 0 to 90 (seconds).
Ice Display
Den
Sets the output density level (Lo,Nor,Hi).
SuP
Sets the supply voltage in the range 200 to 250v.
Ice
Displays current system temperatures.
The software that controls the displays and the other functions of the
machine is stored in 'Flash' memory on the DMX receiver PCB. As new
features become available, this program code can be updated by using the
Martin Uploader programming device for the AVR microprocessor.
HEAVY FOG GLACIATOR
USER
GUIDE
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