Hired-Hand Farm Hand Series: Vent Master 24 - Manual (Page 12)

Part No. 4801-5124 rev 10-03 Farm Hand Vent Master 24 10
While in the Programming Mode and Parameter P3 is shown in the display, Stages
1/12 will be displayed first. Note the red LED next the Stages 1-12 is lighted. After
stetting P3 for Stages 1-12, press the Mode button to set stages 13-24.
9.3 Vent Parameters
This controller runs 1 or 2 vent machines independently. No additional resources – including
external timers – are necessary. A brief overview of the programmable parameters for the
vent machines follows:
P20 -- Vent Machine Time Delay
This setting is the length of time a pressure reading must be out of range
before the controller will operate the vents. This will keep the vents from
constantly cycling open, then closed. If your vents cycle too much,
increase this setting using the plus (+) button. The range for this parameter
is 01 to 20 seconds.
P21 -- Static Pressure Differential
The range over which the Target Pressure will be maintained. The range
for this parameter is from 0.01 to 0.06 “w.c.
P22 -- Tunnel Target Pressure
In tunnel mode, this is the Target Pressure that will be maintained if and
only if SWX 4 of the Tunnel Switches is ON.
P25 -- Tunnel OnPoint
This is the sensor 4 temperature at which the controller will enter tunnel
mode. This is only applicable when tunneling on outside temperature.
P26 -- Tunnel OffPoint
This is the sensor 4 temperature at which the controller will exit tunnel
mode. This is only applicable when tunneling on outside temperature.
9.4 Pressure Ramping Parameters
P30 -- Ramping Mode On/Off
Ramping mode may be turned on or off. If you choose “OFF”, you will not
see the following settings. However, if you choose “ON”, with the plus or
minus button, you turn ramping on, and will have to set the following items.
See Section 7 on ramping for more information on this feature.
P31 -- High Temperature Limit
The outside temperature the controller will use in determining the low range
of its limits.
P32 -- High Temperature Target Pressure
The target pressure when the outside temperature is at the high temperature
limit.
P34 -- Low Temperature Limit
The outside temperature the controller will use in determining the high
range of its limits.
P35 -- Low Temperature Target Pressure
The target pressure when the outside temperature is at the low temperature
limit.
9.5 Pressure Alarm Parameters
P60 -- Low Pressure Alarm
The Low Pressure alarm will send a signal when pressure drops below the
Low Pressure setpoint for greater than 45 seconds. This alarm warns if the