BTU XT-70 - Page 46

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XT-70 Control Panel 46
E2 Parameters Definition:
directional control. Directional control will cause the open output to set a
directional output and the close output to produce a pulse to either drive the
doors open or close. External relays are needed for this mode. A setting of
2 is used for SCX cards and a setting of 3 is for single door with feedback pot
on P8. The default value for this setting is 0.
FREQ_ET Variable Frequency Drive Elapsed Time. This variable is for display only and
can not be changed. If running in the automatic pile differential mode, this
will show how long the fan has run since the last update. When this variable
is equal to the update time on the HMI, the system will increment or decrement
the freq drive setting.
COOL_HRS Setpoint Ramp Cooling Hours. This variable is for display only and can’t be
changed. If in the ramp mode, this variable will show how long it has been
since the last change. When it is equal to the cooling hours on the setpoint
ramp, the ramp will occur and the COOL_HRS will be cleared to 0.
CO2_CONFIG This setting will cConfigure the XT CO
2
input (AN16) for a variety of CO
2
sensor
ranges. The default value for this setting is 0.
A setting of 0 = 0 - 10000 ppm
1 = 0 - 2000 ppm
2 = 0 - 3000 ppm
3 = 0 - 5000 ppm
4 = 0 - 7000 ppm
HEAT_DIFF Heat Differential . This setting will determine when the Heat ON Timer will
increase or decrease. If the plenum temperature is in the window of
Setpoint - Heat_Diff then it will either increase or decrease the amount of heat.
The heat mode will not start until the plenum is .5 degrees below Setpoint.
Once the Heat mode is on then it will not shut off until the Plenum is equal or
greater than the Setpoint. This setting is in 1/10ths of a degree. The default
setting is 2 or 0.2°.
HEAT_UPDATE Heat Update Time is the time period that must elapse before the “heat On time”
will increase or decrease. This setting is in seconds and has a range of 0 -100.
The default setting is 40 seconds.
HEAT_PW Heat Pulse Width is the amount of time that the “heat On time” will increase or
decrease. This setting is in seconds and has a range of 0 - 20. The default
setting is 5 seconds.
Heat Example:
The goal of the heat mode is to maintain the plenum temperature between
setpoint and the heat differential by cycling the Heater on and off. The amount
of time On and time Off will change as needed to maintain a steady plenum
temperature.