TECHNICAL MANUAL
P/N 703073 Rev C
CoolSystems, Inc. – Confidential & Proprietary
Page 10 of 43
Temperature Control for GR2.0 Control Units
GR2.0 Control Units use a mixing valve connected to the temperature control knob. A
ratio of cold water is mixed from the ice box and the warmer return water as shown
below. At “Full Cold”, the pump is drawing 100% of its water from the ice box. At “Full
Warm” the pump is drawing 100% of its water directly from the Wrap, recycling the
return water which continues to be warmed by the body. At knob positions in between,
the pump draws water from both the ice box and the Wrap, proportional to the position
of the knob. Since the water temperature depends on the ice box temperature, return
water temperature (heat load), and knob position, the temperature may drift over time,
and the knob position will not always yield the same temperature each time.
Temperature of the water is measured in two places in the GR 2.0 Control Units;
referencing the figure below, the temperature is measured just before leaving the
Control Unit (T1), and upon returning from the Wrap, back into the Control Unit (T2).
Two different temperatures are displayed on the Control Panel. The “Coldest Wrap
Temp” is the temperature of the water leaving the Control Unit. The “Average Wrap
Temp” is the average of the water leaving the Control Unit (T1) and temperature of the
water returning to the Control Unit (T2).
The following notes regarding the GR2.0 Control Unit also may be of interest:
•
The fluid pump will always run at full speed, regardless of the temperature setting.
•
If the ice box runs low on ice, there may not be enough ice to reach the desired
temperature.
•
When starting a treatment with a GR2.0 Control Unit, it is best to start with the knob
at full cold. This ensures that water is being drawn from the ice box and reduces the
chance of an air bubble entering the fluid pump and stopping fluid flow. If this
happens, an “04 error” (Dry Pump Alarm) will occur. Reference the trouble shooting
section of the manual for advice on clearing this error.
•
There is no maximum temperature setting on a GR2.0. If set to full warm, the water
will not draw water from the ice box, and will continue to recycle return water from
the Wrap which is continuously warmed by the user’s body heat, and the water
temperature in the Wrap could eventually reach body temperature.
CoolSystems
Inc.,
Effective
Date:
12/23/14
