Section 4: Glossary of Control Functions
Humidity Alarms
Humidity alarms are caused when the humidity detected by the remote
sensor in Zone 1 exceeds the programmed High or Low trip-point. Trip-
points are selected in 1% RH increments from the display. Entering 00
disables an alarm. A Humidity Alarm activates the Common Alarm
output.
High Range—up to 80% RH.
Low Range—down to 20% RH.
Humidity Lockout
A Form C contact labeled Humidity Lockout is energized when a
humidity reading exceeds a lockout trip-point. The relay is de-energized
when humidity drops to 2% RH below the High Humidity Trip-point, or
when humidity rises to 2% RH above the Low Humidity Trip-point. To
use this contact for a single control function (increase or decrease
humidity) disable one of the Humidity Alarms.
Inactive Unit
An inactive unit is one that is not programmed to the RAC2-8 system.
This appears in an error message if you try to Override a unit that the
system does not recognize.
Interval
The Interval is the time period (in days) used to program the
Autosequencing and Standby Testing functions. The interval is user
selected from the display. Range—0 to 99 days.
Labels
Each unit may be labeled with a 2 digit number from 01 to 99. If you
prefer something other than 01 through 08, unit labels can be selected
from the display.
Manual Override
A switch located inside the RAC2-8 enclosure turns all units ON. This
action also annunciates an alarm, energizes the Common Alarm output
relay, and energizes the Control Lockout relay. To return to normal
operation, turn this switch off and clear the alarm. Refer to Override for
manual operations from the display.
Modem
The RAC2-8 includes an EIA-232 modem port to provide remote
display of alarms. This same port also allows system monitoring and
programming from a remotely located terminal. Operation from a
remote terminal requires a Password after the “LOG ON: ” prompt. If a
remote terminal is active, alarms are displayed at the terminal instead
of being dialed out. The modem selections such as phone number,
redial interval, etc., are made from a local or remote terminal. Modem
baud rate is selected using switches inside the RAC2-8 enclosure.
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