Emerson MINI-MATE2 user manual 6.10Change Passwords, 6.11Calibrate Sensors

Microprocessor Control

6.9.5Valve Time (for Systems With a Modulating Chilled Water Valve)

This function shows the full valve travel time of the modulating valve on a chilled water system. This is the time it takes for the valve to travel from full closed to full open. It is programmable from 50 to 250 seconds; factory default time is 165 seconds and should not be changed. The full valve travel time is used by the control to determine the appropriate valve position. For example, if the valve travel time is 165 seconds and 50% cooling is being called for, the valve will open for 83 seconds to achieve 50% open.

6.9.6CW Flush (for Systems with a Modulating Chilled Water Valve)

This function shows the interval time at which the system will perform a modulating chilled water valve system flush cycle. The factory default is 24 (hours) and is programmable from 0 (hours) which signifies to never flush, to 99 (hours) which signifies to flush after every 99 hours of valve non-use. If the valve is called on by the control to open within the programmed interval time, the timer will be reset to 0. The flush cycle is active even when the fan is turned off, but power is applied to the unit. When the interval timer reaches the programmed time, the valve will be opened for 3 minutes to flush any contaminants that may have collected in the system.

Table 18 Setup functions, default values and allowable ranges

Function	Default	Range
Restart Time	0.1	0 to 9.9 min
Delay		(0 = manual restart)
C/F Degrees	°F	°C or °F
Humidity Control	Rel	Relative or Absolute
Valve Time	165	50 to 250 seconds
CW Flush	24	0 to 99 hours

6.10Change Passwords

The display will prompt the operator to enter a three digit password when attempting to make changes. The system includes two (2) passwords, one for setpoints and one for setup. The system allows the password to be changed by first entering the default password set at the factory (1-2-3) for setpoints and (3-2-1) for setup. The password function provides system security so that only authorized personnel are allowed to make changes to the system. (If unauthorized changes are being made, the passwords may be compromised and new ones should be selected). The password function can be disabled by setting DIP switch 8 in the wall box to OFF, then resetting power to the unit.

6.11Calibrate Sensors

The temperature and humidity sensors can be calibrated by selecting the CALIBRATE SENSORS menu item. The temperature sensor can be calibrated ±5°F, while the humidity sensor can be calibrated ±10% RH. When calibrating the humidity sensor, the value shown will always be % RH, even though absolute humidity control may be selected. If absolute humidity control is selected, the Normal Status Display will display the adjusted reading. This reading may not agree with the relative humidity reading displayed while in calibration.

If the sensors are subject to frequent wide temperature and humidity swings, it may be necessary to shorten the cycling by increasing the sensor time delay. If the sensors are located too close to the air discharge, they will likely experience rapid swings in measurement. Another method in reducing compressor cycling is to increase the temperature and/or humidity sensitivity.

43 Liebert® Mini-Mate2™