api-usa.com
1220 American Way Libertyville, IL 60048
Phone:
800-942-0315
Fax: 800-949-7502
BSOLUTE
ROCESS NSTRUMENTS, Inc.
Instructions
APD 2055
Calibration
Front-mounted Zero and Span potentiometers for each channel
can be used to compensate for load and lead variations.
1. Apply power to the module and allow a minimum 30 minute
warm up time.
2. Using an accurate voltmeter on terminals 18 and 20, and
then 22 and 24, adjust the excitation voltage fine adjust-
ment potentiometers to the strain gauge manufacturer's
recommended values.
3. Using an accurate calibration source, provide an input to
the module equal to the minimum input required for the
application.
4. Using an accurate measurement device for the output,
adjust the Zero potentiometer for the exact minimum output
desired. The Zero control should only be adjusted when the
input signal is at its minimum. This will produce the cor-
responding minimum output signal. Example: for 4-20 mA
output, the Zero control will provide adjustment for the 4 mA
or low end of the signal.
5. Set the input at maximum, and then adjust the Span pot for
the exact maximum output desired. The Span control should
only be adjusted when the input signal is at its maximum.
This will produce the corresponding maximum output
signal. Example: for 4-20 mA output, the Span control will
provide adjustment for the 20 mA or high end of the signal.
6. Repeat adjustments for both channels for maximum accuracy.
Output Test Function
When the Test button is depressed it will drive the output with a
known good signal that can be used as a diagnostic aid during
initial start-up or troubleshooting. When released, the output
will return to normal.
Each Test Cal. potentiometer is factory set to approximately
50% output. Each can be adjusted to set the test output from
0 to 100% of the output span. Press and hold the Test button
and adjust the corresponding Test Cal. potentiometer for the
desired output level.
They may optionally be externally wired for remote test opera-
tion or a manual override. See wiring diagram at right.
Operation
The APD 2055 accepts two stain gauge inputs and provides
two optically isolated DC voltage or current outputs that are
linearly related to the inputs.
Green LoopTracker
®
input LEDs provide a visual indication that
each signal is being sensed by the input circuitry of the module.
They also indicates the input signal strength by changing in
intensity as the process changes from minimum to maximum.
If an LED fails to illuminate, or fails to change in intensity as the
process changes, check the module power or signal input wiring.
Two red LoopTracker output LEDs provide a visual indication
that the output signals are functioning. They become brighter
as the input and each corresponding output change from
minimum to maximum.
For a current output the red LED will only light if the output loop
current path is complete. For either current or voltage outputs,
failure to illuminate or a failure to change in intensity as the
process changes may indicate a problem with the module
power or signal output wiring. Note that it may be difficult to
see the LEDs under bright lighting conditions.
28 Power AC or DC –
26 Earth Ground
25 Power AC or DC +
26
25
27
28
APD 2055
Channel 1
Channel 2
Strain Gauge to DC
Strain Gauge to DC
Isolated Transmitter
Isolated Transmitter
Test Cal.
Span
Zero
Test
Output
Loop
Tracker
Test Cal.
Span
Zero
Test
Output
Input
Loop
Tracker
Loop
Tracker
Input
Loop
Tracker
Channel 1
Channel 2
®
Excitation
Excitation
14
13
15 16
10
9
11 12
External
Contacts
for Test
Function
–
+ 20V
–
+ 20V
mA
Device 2
R
i
mA
Device 1
R
i
6
5
7
8
2
1
3
4
Current
Sourcing
Output
Ch. 1
Ch. 2
Voltage
Output
–
+
Voltage
Device 1
–
+
Voltage
Device 2
2
1
3
4
Ch. 1
Ch. 2
6
5
7
8
–
+
mA
Device 2
R
i
Loop
Power
Source 2
–
+
+
–
mA
Device 1
R
i
Loop
Power
Source 1
Current
Sinking
Output
Ch. 1
Ch. 2
2
1
3
4
6
5
7
8
+
–
To maintain full isolation avoid combining power supplies in
common with inputs, outputs, or unit power.
See manufacturer's
specifications for
wiring designations.
Shield wires should
be grounded at one
end only.
18
17
19 20
Excitation
+
Strain
gauge
Signal
–
Excitation
–
22
21
23 24
Excitation
+
Strain
gauge
Signal
–
Excitation
–
Precautions
WARNING! All wiring must be performed by a qualified electrician
or instrumentation engineer. See diagram for terminal designa-
tions and wiring examples. Consult factory for assistance.
WARNING! Avoid shock hazards! Turn signal input, output, and
power off before connecting or disconnecting wiring, or remov-
ing or installing module.
Précautions
ATTENTION! Tout le câblage doit être effectué par un élec-
tricien ou ingénieur en instrumentation qualifié. Voir le dia-
gramme pour désignations des bornes et des exemples de
câblage. Consulter l'usine pour assistance.
ATTENTION! Éviter les risques de choc! Fermez le signal
d'entrée, le signal de sortie et l'alimentation électrique avant
de connecter ou de déconnecter le câblage, ou de retirer ou
d'installer le module.
Electrical Connections
Polarity must be observed for signal wiring connections. If the
input and/or output do not function, check wiring and polarity.
Each product is factory configured to your exact input and
output ranges as indicated on the serial number label.
Outputs
For milliamp ranges determine if your devices provide power
to the current loop or if the loop must be powered by the APD
module. Typical voltage may be 9-24 VDC at your device's
terminals if it provides power to the loop.
Bridge Input Channel 1
– Te Terminal
Strain gauge signal input
17
(
+)
19 (
–)
Excitation voltage
18 (
–)
20
(
+)
Input 1, Bridge, Strain Gauge, Load Cell
Refer to wiring diagram at right and strain gauge manufac-
turer’s data sheet for wiring and color-coding. Polarity must
be observed when connecting input. Sensor shield wire (if
equipped) should be grounded at one end only.
The excitation voltage is factory set and should match the sen-
sor manufacturer's recommendations. A front potentiometer
allows approximately ±10% fine adjustment of the excitation
voltage.
CAUTION: Never short the excitation leads together. This will
cause internal damage to the module.
API maintains a constant effort to upgrade and improve its prod-
ucts. Specifications are subject to change without notice. Consult
factory for your specific requirements.
Bridge Input Channel 2
– Te Terminal
Strain gauge signal input
21
(
+)
23 (
–)
Excitation voltage
22 (
–)
24
(
+)
Input 2, Bridge, Strain Gauge, Load Cell
Refer to wiring diagram at right and strain gauge manufac-
turer’s data sheet for wiring and color-coding. Polarity must
be observed when connecting input. Sensor shield wire (if
equipped) should be grounded at one end only.
The excitation voltage is factory set and should match the sen-
sor manufacturer's recommendations. A front potentiometer
allows approximately ±10% fine adjustment of the excitation
voltage.
CAUTION: Never short the excitation leads together. This will
cause internal damage to the module.
Mounting to a DIN Rail
Install module vertically on a 35 mm DIN rail in a protective
enclosure away from heat sources. Do not block air flow.
1. Tilt front of module down and posi-
tion the lower spring clips against
the bottom edge of DIN rail.
2. Push front of module upward until
upper mount snaps into place.
Removal
Avoid shock hazards! Turn signal
input, output, and power off.
1. Push up on bottom back of module.
2. Tilt front of module downward
to release upper mount from top
edge of DIN rail.
3. The module can now be removed
from the DIN rail.
Spring Clips
Upper Mount
Module Power Terminals
Check label for module operating voltage to make sure it
matches available power. The power supplies are fuse protect-
ed and the unit may be returned to API for fuse replacement.
When using DC power, either polarity is acceptable, but for
consistency, wire positive (+) to terminal 25 and negative (–)
to terminal 28.
Device for Output Channel 1
Terminal Terminal
Voltage input device.
3 (
–)
4
(
+)
Unpowered or passive mA input device.
APD module provides the loop power.
3 (
–)
4
(+20 V)
mA input device powers the current loop.
2 (
–)
3
(
+)
Device for Output Channel 2
Terminal Terminal
Voltage input device.
7 (
–)
8
(
+)
Unpowered or passive mA input device.
APD module provides the loop power.
7 (
–)
8
(+20 V)
mA input device powers the current loop.
6 (
–)
7
(
+)
Cu 60/75°C
conductors
14 AWG
max.
