Mydax, Inc.
1M150W
Water Cooled Chiller
Designed for Lockheed Martin
10
ALARM & RROR MESSAGES
A unique feature of Mydax systems is the error messages displayed on the 2 by 40-character liquid crystal display
(LCD). The microprocessor constantly checks various points and parameters throughout the system and automatically
displays messages when error conditions are sensed. Many displays are announced by an audible alarm and LED
indicator. The error message persists until the fault condition is resolved, provided that the fault condition was not fatal,
resulting in a system shutdown.
Condenser Hot
Indicates high discharge pressure condition with temperature over +50
°
C. This is a warning message
only. A separate mechanical over pressure switch, part of the safety interlock loop, shuts the system
down in case of an over pressure condition. The purpose of this message is to allow maintenance
workers to correct the problem at an early stage. (Caused by a clogged filter, low or warm condenser
cooling water flow or condenser scale build-up.)
Fill Tank #1
Indicates low tank liquid level; this is a warning message.
Extreme Temp
Indicates that the reservoir temperature is either more than 10
°
C above the highest allowable setpoint
(+50°C) or that it is too close to freezing (+4°C). The microprocessor shuts down the system with a
fatal alarm.
Push Reset
Indicates that a fatal alarm in the interlock circuit has occurred and the operator must push the “Reset”
button on the front face of the chiller in order to restart the system.
A series-wired safety interlock loop protects all Mydax systems, disconnecting AC power from nearly
all circuitry. The loop consists of the refrigerant pressure switch and the "tank empty" float switch. If
any link in the loop is opened, the "Push Reset" error message is displayed. Once the fault is
corrected, the Reset button must be used to re-establish loop integrity.
AC Power Fault:
Generated by the Line Voltage Monitor, the system is shut down to prevent damage due to: low
AC voltage (<440V) or unbalance (4% for > 5 seconds), phase loss or phase reversal (> 100
milliseconds). On initial power-up, reverse two lines to achieve proper phase sequence.
Low AC Line
Indicates a low voltage condition exists on the input AC line.
Open RTD
Indicates that an RTD connected to the M1002 Input Board has failed and that the system has shut
down to prevent damage due to lack of data. The RTD at fault may be located by accessing Test Panel
8. The RTD must be replaced for the system to operate again.
Low Flow
Indicates that the flow rate, in the recirculation loop, is lower than 5GPM; this is a value set in the
firmware. This shuts down the chiller, with a fatal alarm, to protect the pump.
