IntelliPack Series 811T Transmitter/Alarm User's Manual DC Voltage/Current Input
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1.
Power:
Refer to Electrical Connections Drawing 4501-640.
Variations in power supply voltage within rated limits has
negligible effect on module accuracy. For supply
connections, use No. 14 AWG wires rated for at least 75
C.
The power terminal is diode-coupled for reverse polarity
protection.
2.
DC Voltage/Current Inputs (Without AC Current Sensor):
Connect input(s) per Drawing 4501-640. Observe proper
polarity (see label for input type). An excitation supply is
provided at the input for powering two-wire transmitters.
3.
AC Current Input (Optional):
Refer to Drawing 4501-633 to
connect the optional AC current sensor. The sensor is
typically mounted near the AC current being measured and
will transmit a low level DC milliampere signal to the module.
This allows the module to be mounted remote from the AC
signal and sensor and connected using small gauge wire.
The sensor output (Red/Black) wires can be shorted, open-
circuited, or removed from the transmitter input terminals,
without hazard to personnel or to the sensor.
AC Current Sensor:
Per Table 2 on Page 4, loop the
required number of turns through the toroid for the full-scale
current range required by your application. Use the cable tie
provided with the sensor to mechanically secure it.
DANGER:
If the AC current sensor is used with an AC
Current Transformer (C.T.), disconnect power from the
C.T., or short the output of the C.T., before removing the
wire going through the AC current sensor. If this is not
done, an open circuited C.T. will generate hazardous high
voltages and possible C.T. damage.
4.
Analog Output Connections
: Wire outputs as shown in
Electrical Connections Drawing 4501-640. For voltage
output, you must also install a jumper between the output “I+”
and “JMP” terminals (pre-installed from the factory). Remove
this jumper for current output.
5.
Output Relay Contacts (811T-1500)
: Wire relay contacts as
shown in Electrical Connections Drawing 4501-640. See the
“Alarm Relay Specifications” for power capacity. If
necessary, an interposing relay can be used to switch higher
currents as shown in Interposing Relay Connection Drawing
4501-646.
Electromechanical Relay Contact Protection:
To
maximize relay life with inductive loads, external protection is
required. For DC inductive loads, place a diode across the
load (1N4006 or equivalent) with cathode to (+) and anode to
(-). For AC inductive loads, place a Metal Oxide Varistor
(MOV) across the load. See Relay Contact Protection
Drawing 4501-646 for details.
IMPORTANT:
Noise and/or jitter on the input signal has the
effect of reducing (narrowing) the instrument’s deadband and
may produce contact chatter. The long term effect of this will
reduce the life of mechanical relays. To reduce this
undesired effect, you should increase the effective deadband.
Note that the input averaging function of this transmitter may
also be used to reduce contact chatter. The configurable
relay time delay may also help eliminate relay chatter.
6.
Grounding:
See Electrical Connections Drawing 4501-640.
The module housing is plastic and does not require an earth
ground connection. However, there are mounting positions
on the input and output terminals to connect cable shields,
plus earth ground. These connections are isolated from the
internal circuit and are recommended to minimize noise and
help protect the unit from damaging I/O transients.
WARNING:
For compliance to applicable safety and
performance standards, the use of shielded cable is
recommended as shown in Drawing 4501-640. Further, the
application of earth ground must be in place as shown in
Drawing 4501-640. Failure to adhere to sound wiring and
grounding practices may compromise safety & performance.
3.0 MODULE CONFIGURATION
This transmitter/alarm module needs to be configured for
your application. Configuration is done using Acromag’s
Windows 95/98/ME/NT/XP/2000 IntelliPack Configuration
Program and Serial Port Adapter. Transmitter configuration
details are included in the IntelliPack Transmitter Configuration
Manual (8500-570). Field configuration of transmitter zero & full-
scale, plus setpoint & dropout (811T-
1500 units), via the module’s
push-
buttons and LED’s is covered below.
FIELD CONFIGURATION
This program mode allows adjustment to key transmitter
configuration and alarm parameters in the field, without having to
connect a host computer. Field reprogrammability of zero & full-
scale (scaling parameters), plus alarm setpoint & deadband
(Model 811T-1500) is accomplished via the transmitter/alarm
module’s “SET”, “MODE”, “UP”, and “DOWN” push buttons, and
the zero/full-
scale and relay LED’s (see Drawing 4501-642).
Equipment Required
•
An accurate input source (voltage or current) adjustable over
the configured input range. This source must be accurate
beyond the module specifications for best results. For
voltage inputs, use a voltage source with an output
impedance of 100
or less.
•
An accurate current or voltage meter is also required to
monitor the output level. This meter must be accurate
beyond the module specifications for best results.
Note:
The module’s input range must already be set via the
IntelliPack Configuration Software. Input levels outside of
the configured input range will not be accepted for zero, full-
scale, setpoint, or dropout calibration. Since input levels
cannot be validated during field programming, entering
incorrect signals can produce an undesired output response.
Install a jumper between the output “I+” and “JMP” terminals
for voltage output. Remove this jumper for current output.