Mydax, Inc.
1M150W
Water Cooled Chiller
Designed for Lockheed Martin
12
maintain temperature stability, and give the magnitude and timing of the change.
The center of the display shows readings for the RTD "Zero" and "Gain" calibration resistors. Precision 100
Ω
and 120
Ω
resistors (0.1% tolerance or better, representing ideal nominal RTD's) are used as a reference.
TEST PANEL #4:
This display shows auxiliary voltmeter readings of Ext 1, Ext 2 and Ext 3. Ext 1 is the voltage reading from the
integrated flowmeter. Ext 2 and Ext 3 are unused. VAC is the 24 VAC internal control voltage. A typical
value is in the range of 22.00 to 28.00. To the right of this value is an unused single-digit number ranging from
0 to 3. At the far right of this display is a time indicator in seconds. The timer stops at 255 seconds and is used
internally for turn on routine procedures.
TEST PANEL #5:
This diagnostic shows the
Output
(Tank) RTD temperature in
°
C, the Output Setpoint temperature and Output
temperature slope. Slope is a measure of the direction and amount of the output temperature change per 60
seconds.
TEST PANEL #6:
This panel shows the trip point, above which, the Flow-OK contact is engaged; the trip-point is settable from 2
to 25 GPM by using the UP/DOWN (
↑
,
↓
) arrows on the keypad. By using the data from the in-line turbine flow
meter, the microprocessor will disengage the Flow-OK relay below the selected GPM. The output of the relay is
wired to a BNC connector, labeled "Flow OK", located on the rear panel of the unit. The shield and center pin
are the normally-open contact, which closes when flow is above the trip point.
The temperature of the
Input
fluid (return) to the chiller is monitored by an RTD, and displayed here for
reference. See the drawing
Chiller Fluid Schematic
at the end of this manual.
TEST PANEL #7:
This left-most six numbers of the display shows voltmeter readings for up to 3 optional water resistivity monitor
interface raw data outputs. Only the first column is used in this system.
The refrigerant type that the control system is calibrated for is shown. For example:
R134A
The two numbers at the top, far right-hand side of this display represent the internally computed maximum
evaporator temperature and a counter ranging from 0 to 99, which are used to adjust the valve drives and
regulate the superheat temperature.
The second line of the right side of this display indicates the status of the lithium battery, mounted on the
M1001 circuit board, used to run the system's elapsed run-time clock depicted in Test Panel 8 and the run/event
recorder depicted in Test Panel 9. A "Bat. OK" message indicates that the battery is operational, while a "No
Bat." message indicates that the battery is dead and should be replaced.
-2.583 -0.000 -0.000 +24.13 0 255
Ext 1 Ext 2 Ext 3 VAC Secs
24.95
25.0
0.0
Tank
Set
DgMin
15 12.45°C
Flow Relay Gpm
Input
- 0.432 -0.000 -0.000 R134A - 5.00 0
+ 0.485
-0.000
-0.000
Bat. OK
