Wiring and Installation
APD 4058
Settings for Push-Pull Load Cells
The input range can be thought of as a percentage scale.
Zero percent of the signal range will be a negative number for
push-pull load cells. The high end of the signal will be a posi-
tive number. Add these together to get the span (100% of the
total signal range).
For example, if a load cell has a 1.5 mV/V sensitivity with 10 V
excitation, the range for push-pull will be –15 mV to +15 mV.
This is a span of 30 mV and we would select 30 mV as our input
range. If the range does not match up to what is in the table,
select the next highest input range setting.
For push-pull applications it is common to use a ±5 V or ±10 V
output setting. Use the table below to find your switch settings.
We also need to use "Offset Switch C" to bring the negative
end of our input range up by 50% to 0 mV. The closest set-
ting is position "B" 45%. This can be adjusted to 50% with
the zero potentiometer when output calibration is done.
M01 Option: Internal Calibration Resistor
The APD 4058 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 4058 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 4058.
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
When no sense leads are used, jumper terminals 6 and 12.
With Sense Leads
Some bridges or load cells have one or two sense leads.
Sense leads allow the APD 4058 to compensate for leadwire
resistance effects. 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.
CAUTION: To maintain full isolation avoid wiring DC power sup-
plies 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
(
+)
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.
Spring Clip
Upper Mount
Lower Mount
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 4058
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 4058
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
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.
Cu 60/75°C
conductors
14 AWG
max.
1
2 3 4
5 6
7 8
9 10 11 12
13 14
15
16
Input
Cal. and Sense
Output
Power
api-usa.com
1220 American Way Libertyville, IL 60048
Phone:
800-942-0315
Fax: 800-949-7502
A
A
BSOLUTE
BSOLUTE
P
P
ROCESS
ROCESS
I
I
NSTRUMENTS
NSTRUMENTS
Wire terminal
torque
0.5 to 0.6 Nm or
4.4 to 5.3 in-lbs
Module powers mA output loop
* Do not make connections
to unused terminals!
* Do not make connections
to unused terminals!
