Automated Logic R683 Petunjuk Teknis - Halaman 9

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Universal Inputs

The R683 provides eight universal inputs which are
wired as shown in Figure 12. These inputs are jumper
selectable and may accept the following signals:
Thermistor: 10k Ohm @ 77 °F (Precon type 2).
0-5 VDC: The output impedance of a 0-5 VDC source
should not exceed 10k Ohms. The input impedance of
the R683 is approximately 1M Ohm.
0-20 mA: 24 VDC loop power, 250 Ohm input
impedance. A total of 200mA is supplied to these inputs
for 4-20mA transducer wiring. If the total current
required by all of the transducers is greater than 200mA,
an additional power supply is needed. In order to check
this, measure the voltage between the "B" terminal and
the ground of the module. It should read between 18VDC
and 24VDC. If it reads less than 18VDC then the total
current required is greater than 200mA.
Dry Contact: 0.5 mA maximum sense current.
NOTE: Some current switches which are not true dry
contact closures may not go to zero when the switch is
closed. Any switch which has more than 412 Ohms
effective resistance (0.2 V) when closed must have an
interposing mechanical relay.
NOTE: In most cases, a 4-20 mA passive transducer does
not require an external power supply (see Figure 6). In
some special cases, when the module's power is limited, a
4-20 mA passive transducer does require and external
power supply to avoid power consumption from the
module.
Table 1
Max Length
Type Input
(feet)
0-5 VDC
50
Thermistor/Dry
50
Contact
Enhanced Zone
50
Sensor
0-20 mA
150
Rev. (30-JAN-98) • RLM v4.7
Gauge Wire
Shielding
(AWG)
shielded
24
(grounded to Gnd
(minimum)
terminal)
shielded
24
(grounded to Gnd
(minimum)
terminal)
24
unshielded
(minimum)
20
unshielded
(minimum)

Procedure

NOTE: For ALC room sensors, place a 10 V, 1 W Zener
diode (1N4740A) in series with the sensor (as shown in
Figure 10). If you are unable to obtain these diodes
contact Technical Support.
1.
Turn the R683's power switch OFF.
2.
Check the sensor wiring for shorts and grounds.
3.
Terminate the sensor wires to the proper input
terminals as indicated in Figure 12.
4.
Set the input configuration jumper (for each input)
according to the type of sensor required (see
Figure12).
CAUTION: Jumper orientation is critical, see
Figure 13 for proper jumper positioning.
Figure 13: Correct Jumper Orientation
5.
Turn the R683's power switch ON.
6.
Verify the input by measuring the voltage between
the A terminal of the analog input (see Figure 12)
and the Gnd terminal of the power wiring. Input
voltages should range between 0.489 V and 3.825 V
for thermistors and 1.0 V and 5.0 V for 4-20 mA
devices.
7.
Enter the channel number, offset, and gain on the
FB's parameter page (see "Channel Numbers").
© 1995-98 Automated Logic Corporation
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