24431
Rev. A
10/12
http: www.networketi.com
Environmental Technology, Inc.
77 of 94
Automatic Air Dehydrator
ADH
®
SIROCCO™
Instruction Manual
Alarm conditions 21 and 22, “Too Cold” and “Too Hot” respectively, will actually
be signaled to the operator before the temperature is extreme enough to cause
pumping to actually stop. Done intentionally, this gives the operator some time to
investigate and fix the problem before pressurization is lost. The unit will indicate
alarm condition 21, “Too Cold,” at 32°F, although pumping does not actually stop
until 23°F. Similarly, at the high end, the unit will indicate alarm condition 22,
“Too Hot,” at 155°F, although pumping does not actually stop until 170°F.
The three alarm relays are reverse acting, meaning that the state they take when
there is an alarm is the same state they take when there is no power. Alarm
relay 1 is a “Summary” alarm, meaning that any of the 22 alarm conditions will
cause it to activate. Alarm relay 2 is a Low Pressure alarm. Alarm relay 3 is set
at the factory as the Dew Point alarm by default, though it is also configurable by
the operator, as desired.
As it is used in facilitating the communication of the various alarm conditions to
the operator, the pin assignments and descriptions for the DB15 connector are
listed in Table 2 below.
PIN DESCRIPTION
1
RELAY 1 Closed on alarm
2
RELAY 1 Open on alarm
3
RELAY 2 Closed on alarm
4
RELAY 2 Common
5
RELAY 2 Open on alarm
6 Not
used
7 Not
used
8 Not
used
9
RELAY 1 Common
10
RELAY 3 Common
11
RELAY 3 Open on alarm
12
RELAY 3 Closed on alarm
13 Not
used
14 Not
used
15 Not
used
Table 2. DB15 PIN ASSIGNMENTS
AND CONNECTION DESCRIPTIONS.