Wiring, Installation, Calibration
APD 4059
M01 Option: Internal Calibration Resistor
The APD 4059 M01 has a user-specified internal calibration
resistor. A switch on the front of the module allows switching
of the APD's internal calibration resistor in or out of the circuit.
The sensor manufacturer should provide the percentage of full-
scale output for the transducer when using the APD's internal
resistor for calibration.
M02 Option: Load Cell Calibration Resistor
The APD 4059 M02 has provisions for a load cell with its own
calibration resistor. A switch on the front of the module allows
switching of the load cell internal calibration resistor in or out
of the circuit.
Refer to the load cell manufacturer's specifications and the
wiring diagram when connecting a transducer with its own
internal calibration resistor.
The transducer's calibration resistor wires are connected to
terminals 5 and 11 on the APD 4059.
If the transducer only has one calibration resistor wire, connect
it to terminal 5.
Input
Refer to strain gauge manufacturer’s data sheet for wire color-
coding and identification. Polarity must be observed when
connecting inputs.
CAUTION: Do not miswire the load cell and never short the
excitation leads together. This will cause internal damage to
the module.
No Sense Leads:
If no sense leads are used, jumper terminals
6 and 12.
With Sense Leads:
Some bridges or load cells have one or two
sense leads. This allow compensation for leadwire resistance.
Connect the sense leads if used. Polarity must be observed.
Never jumper terminals 6 and 12 when using sense leads.
Output
Polarity must be observed when connecting the signal output.
If your device accepts a current input, determine if it provides
power to the current loop or if it must be powered by the APD
module. Use a multi-meter to check for voltage at the device's
input terminals. Typical voltage may be 9-24 VDC.
Module Power
Check model/serial number label for module operating voltage
to make sure it matches available power. Connect power last.
When using DC power, either polarity is acceptable, but for
consistency with similar API products, positive (+) can be wired
to terminal 13 and negative (–) can be wired to terminal 16.
Connect I/O wiring before power wiring.
CAUTION: To maintain full isolation avoid wiring DC power
supplies in common with output and unit power.
Type of Device for Output
– Term.
+ Term.
mA (current) input device that powers
the current loop. Switch E set to “I”.
2 (
–)
3
(
+)
mA (current) input device that is pas-
sive. APD module provides the loop
power. Switch E set to “I”.
3 (
–)
4
(+20 V)
Measuring/recording device accepts a
voltage input. Switch E set to “V”.
3 (
–)
4
(
+)
14
13
15
16
13 Power AC or DC
+
14
Earth Ground
16 Power AC or DC –
Module Power
Current sinking output
switch E set to “I”
External device provides
power to output loop
2
1
3
4
–
+
+
–
Loop
Power
Source
+
–
4-20 mA
Device
R
i
Current sourcing output
switch E set to “I”
+20 V at terminal 4
2
1
3
4
Passive
4-20 mA
Device
R
i
–
+20V
Voltage output
switch E set to “V”
2
1
3
4
Voltage
Device
–
+
Output Wiring
M02 option
for load cell
with built-in
cal. resistor.
Connect to
terminals 5
and 11
No Sense Leads
Jumper 6 to 12
ONLY if sense leads
are NOT used
6
5
7
8
10
9
11 12
Strain
Gauge
Span
Zero
Test
Output
Input
APD 4059
Strain Gauge to DC
Isolated Transmitter
Excitation
V
0
+
V
0
–
V
EX
–
V
EX
+
Exc
+
Exc –
Sig
–
Sig
+
Test Cal.
Sig
+
Exc –
Sig –
Exc
+
Cal.
With Sense Leads
Sense
+
Sense –
Sense
+
Sense –
6
5
7
8
10
9
11 12
Strain
Gauge
Span
Zero
Test
Output
Input
APD 4059
Strain Gauge to DC
Isolated Transmitter
Excitation
V
0
+
V
0
–
V
EX
–
V
EX
+
Exc
+
Exc –
Sig
–
Sig
+
Test Cal.
Sig
+
Exc –
Sig –
Exc
+
Cal.
M02 option
for load cell
with built-in
cal. resistor.
Connect to
terminals 5
and 11
Cu 60/75°C conductors 14 AWG max.
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.
Allow 1" (25 mm) above and below housing vents for air
circulation.
1. Tilt front of module downward and
position against DIN rail.
2. Clip lower mount to bottom edge of
DIN rail.
3. Push front of module upward until
upper mount snaps into place.
Removal
1. Push up on the bottom back of the
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.
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1220 American Way Libertyville, IL 60048
Phone:
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A
A
BSOLUTE
BSOLUTE
P
P
ROCESS
ROCESS
I
I
NSTRUMENTS
NSTRUMENTS
Module powers mA output loop
Basic Calibration
The Zero, Span, and Excitation potentiometers are used to cali-
brate the output. This calibration procedure does not account
for offsets or tare weights. If your system has an offset, tare
weight or deadweight, refer to the Offset Switch procedure.
Input and output ranges, if specified on your order, are factory
pre-configured (at 24°C ±1°C).
Note: Perform the following calibration procedure any time
switch settings are changed.
To achieve optimum results, the system should be calibrated
using an accurate bridge simulator, pressure calibrator, or
calibration weights depending on the application.
1. Apply power to the module and allow a minimum 20 minute
system warm up time.
2. Using an accurate voltmeter across terminals 10 and 12,
adjust the Excitation voltage potentiometer on front of the
APD 4059 for the exact voltage desired.
3. With the input set at zero or the minimum, adjust the front
Zero pot for a zero or low-end output (for example, 4 mA for
a 4-20 mA output or –10 V with a ±10 V output).
4. The zero pot may also be adjusted for a zero reading on
the output display instrumentation, e.g. control system or
process indicator. Adjusting the zero pot this way eliminates
calibration errors in the display instrumentation.
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.
Push-Pull Calibration
1. Apply power to the module and allow a minimum 20 minute
system warm up time.
2. Using an accurate voltmeter across terminals 10 and 12,
adjust the Excitation voltage potentiometer to the exact volt-
age desired.
3. Connect the precision resistor between Exc+ and Sig+. This
will simulate the cell under tension and apply negative volt-
age to the input.
4. Adjust the Zero control to –80% output since the resistor is
scaled for 80% of defection.
5. Remove the precision resistor.
6. Connect the precision resistor between Exc– and Sig–. This
will simulate the cell under compression and apply a posi-
tive voltage to the input.
7. Adjust the Span control for +80% output since the resistor
is scaled for 80% of defection.
8. Remove the precision resistor. The output should be near
0 V. It is possible for zero to be off a small amount due to
stacking of tolerances within both the load cell, wiring, and
the APD 4059.
* Do not make connections to unused terminals!
Colors shown are an example only.
See manufacturer's specifications for wiring designations.
Shield wires should be grounded at one end only
To maintain full isolation, avoid combining power supplies
in common with input, output, or unit power.
1
2 3 4
5 6
7 8
9 10 11 12
13 14
15
16
Input
Cal. and Sense
Output
Power
Wire terminal
torque
0.5 to 0.6 Nm or
4.4 to 5.3 in-lbs
* Do not make
connections to
unused terminals!
* Do not make connections
to unused terminals!
1 strain gauge shown. Connect up to 4 in parallel if all leads are
equal length. Unequal length leads or strain gauges with calibra-
tion variances may require sum box SG-EQ4 to aid in equalization.
Spring
Clip
Upper
Mount
Lower
Mount
