CAMCORP CAM-AIRO Vertical Cartridge - Manual (Page 30)

when routing the air hoses to ensure that any potential con-
densation or moisture will not drain into the sensor. Where
heavy condensation is present, a drip loop or an in-line filter
should be installed to ensure long term operation.
2.2 Connections
When a pressure module is installed, the 4-20 mA process
signal and the alarm relay contacts are available. The circuit
may be used with the internal 24-volt power source or with
an external source. In either case, the 4-20 mA circuit is iso-
lated from ground and other signals. The alarm relay con-
tacts are isolated, normally open contacts. Pressure connec-
tions may be made to the stepped hose barbs with either
1/8
″
or 3/16
″
I.C. tubing. The following subparagraphs
describe the external switch connections. Refer to figure 1 for
switch connection illustration.
2.3 Pressure Module Installation
The pressure module is attached to the Master Controller
using integral connectors on both units. The insertion ports
for the pressure module are located in the upper left quad-
rant of the DCT1000 Master Controller. The pressure mod-
ule can be removed by compressing the retaining clips on
each end of the module, then gently pulling the module out
of the master controller board.
When inserting the module, the following procedure should
be adhered to insure proper installation:
• Examine the bottom of the pressure module and note the
orientation of the connectors.
• Align the module so that these connectors match the con-
nector receptacles on the controller board.
• Orient the module with the four alignment pins over their
respective mounting holes.
• Gently press the module into the connectors and snap the
retaining clips on either end of the module into their slots.
• Always install and service this device with the power off and
a lockout installed if required. “Hot” plugging the pressure
module into an operating system may damage the system or
cause the calibration parameters to be erased.
Caution: Do not force the module into the connec-
tors. Forcing the insertion may damage the connec-
tors. Properly aligned, the module should snap into
place.
2.3.1 Alarm Mode Switch Connection
The auto alarm reset is controlled by the alarm mode switch
connection. To enable the auto alarm reset the alarm mode
input must be connected to a common connection. A jumper
may be used when auto alarm reset is always active. A
switch may be used if there are times that the auto alarm
reset must be disabled. The switch must be an isolated con-
tact and wired such that no connection is made between
either of the wires and ground.
2.3.2 Alarm Reset Switch Connection
The alarm may be reset either by pressing the Alarm Reset
button on the control panel or by an external switch con-
nected between the alarm-reset terminal and one of the
common terminals. The alarm reset will only operate if the
pressure module is installed and the pressure has returned to
a normal condition.
2.3.3 Connecting the 4-20 mA Loop
The pressure module provides an isolated 4-20 mA output,
which may be used to remotely monitor the differential pres-
sure across the dust bags or cartridges. The connection is
made on the master control module at the terminal block
designated for this signal. The connection is a 2-wire config-
uration with the option of using either an external 15 to 35
VDC power source or using the internal 24 VDC source.
2.3.4 Connecting the Alarm Relay
With the pressure module installed, a relay contact is provid-
ed for controlling an external alarm. This relay is a single
form-A contact. It is activated when either the high alarm
threshold is exceeded, or the pressure drops below the low
alarm threshold. The connection is made at the two-pin con-
nector TB5.
2.4 Demand Mode using a DCP100/200
Pressure Module
The DCT1000 system may be configured to be a self-con-
tained on-demand control system with the installation of the
DCP100 pressure module. When this module is installed, the
master controller detects it and automatically sets the system
to an on-demand mode, enabling features associated with
the pressure sensor. The following subparagraphs describe
the setup and operation of these pressure related features.
2.4.1 Manual Override Switch Connection
The manual override function allows the system to be set to
the run mode regardless of other conditions. This mode is
enabled when the manual override terminal and common are
connected. It is disabled when they are disconnected. If the
controller is to be run in continuous mode, a jumper wire may
be wired across these terminals. When manual override is
needed on a periodic basis, wire a SPST toggle switch
between the manual override terminal and the common ter-
minal.
2.4.2 Down Time Clean Connection
The down time clean operation forces the system into a run
cycle for a programmed length of time between 0 – 255 min-
utes. The operation is initiated by connecting the down time
clean terminal to a common terminal. This function is best
accomplished through use of an external normally open
switch.
2.4.3 Connecting Multiple Timer Boards
Both master controller boards and slave boards can have up
to a maximum of 22 channels each. The system may be
expanded up to 255 channels using master controller boards
and slave boards. The DCT1000 will automatically detect the
total number of channels involved and make their outputs
4