Mantracourt SGA/A, SGA/D User Manual
SGA/A & SGA/D
Strain Gauge / Load Cell Amplifier /
Signal Conditioner
Issue 7 PCB onwards
User Manual
www.mantracourt.co.uk
SGA/A & SGA/D Manual
Contents
Chapter 1 Introduction to SGA/A & SGA/D ......................................................................................... 2
The Strain Gauge Amplifier SGA ....................................................................................................... 2
Figure 1.1 SGA Signal Conditioner ..................................................................................................... 2
Chapter 2 Installing the SGA/A & SGA/D ............................................................................................ 3
Pre Installation............................................................................................................................ 3
Figure 2.1 Dimensions ................................................................................................................... 3
Cabling...................................................................................................................................... 4
Power Connection ........................................................................................................................ 4
Figure 2.2 Power Connection ........................................................................................................... 4
Figure 2.3 Input (Sensor) Connections ................................................................................................ 5
Table 2.1 ................................................................................................................................... 5
Output Connections ...................................................................................................................... 6
Figure 2.4 Output Connections ......................................................................................................... 6
Chapter 3 Switch Settings ............................................................................................................. 7
Figure 3.1 Output Settings–Switch 4................................................................................................... 7
Table 3.1 Output Option ................................................................................................................ 7
Table 3.2 Switch 4........................................................................................................................ 7
Table 3.3 ................................................................................................................................... 8
Output Filter Settings –Switch 3........................................................................................................ 8
Table 3.4 Switch 3........................................................................................................................ 8
Table 3.5 ................................................................................................................................... 9
Output Current Mode and Input Filter Settings – Jumpers JP1, JP2 & JP3 ..................................................... 9
Figure 3.2 .................................................................................................................................. 9
Span (Gain) Setting Switch SW1 .......................................................................................................10
Table 3.6 – SW1 ..........................................................................................................................10
Table 3.7 .................................................................................................................................. 11
Shunt Calibration Switch SW1/8 ......................................................................................................11
Table 3.8 .................................................................................................................................. 11
Figure 3.3 ................................................................................................................................. 11
Zero (Offset) Setting Switch SW2 .....................................................................................................11
Table 3.9 .................................................................................................................................. 12
Table 3.10.................................................................................................................................12
Chapter 4 Calibration ..................................................................................................................13
Output .....................................................................................................................................13
Zero Offset................................................................................................................................ 13
Sensitivity ................................................................................................................................. 13
Figure 4.1 Calibration Connections using Millivolt Source........................................................................ 15
Chapter 5 Troubleshooting ...........................................................................................................16
Chapter 6 Product Care ...............................................................................................................18
Chapter 7 Glossary .....................................................................................................................19
Chapter 8 Specifications for SGA/A & SGA/D Load Cell Amplifiers...........................................................22
CE Approvals.............................................................................................................................. 23
Warranty .................................................................................................................................. 23
Figure 8.1 Connection Details .........................................................................................................24
Other Mantracourt Products..........................................................................................................25
Mantracourt Electronics Limited SGA/A & SGA/D User Manual
1
Chapter 1 Introduction to SGA/A & SGA/D
Load Cells
Strain Gauges
Torque Transducers
Pressure Transducers
The Strain Gauge Amplifier SGA
The SGA is a Strain Gauge Amplifier, converting a strain gauge input to a Voltage or current output – otherwise
known as a Signal conditioner.
The SGA provides a wide range of signal conditioning for Strain gauges, Load cells, Pressure and Torque transducers.
Figure 1.1 SGA Signal Conditioner
Inputs
POWER
SUPPLY
110/230 V AC
18-24V DC
STRAIN
GAUGE
AMPLIFIER
INPUT
OUTPUT
±10V
±5V
0-5V
0-20mA
4-20mA
Offered in two versions, the SGA/A for 110/230V AC or 18-24V DC operation and the SGA/D which is DC powered
only.
Transducer SENSITIVITY of between 0.1 mV/V and 30 mV/V are possible.
This is achieved by a combination of gain (span) DIP switches and associated fine adjustment by a potentiometer.
Similarly transducer zero OFFSET and SCALE DEAD BAND of up to 79% can be compensated for in the module.
This is achieved again by a combination of zero DIP switches and associated fine adjustment by a potentiometer.
The module has built-in FILTERS to cancel the field effects of vibration, agitation and electrically noisy
environment.
The on-board low pass filter can be switched in and adjusted (from 1Hz to 5kHz) using a series of DIP switches.
A wide range of proportional output options for currents and voltages can be configured by DIP switch settings.
Both the AC and DC versions are based on a common board and are mounted in an IP65 (NEMA 4X) ABS case.
Mantracourt Electronics Limited SGA/A & SGA/D User Manual
2
Chapter 2 Installing the SGA/A & SGA/D
Pre Installation
See Specification details in Chapter 8 for details of Environmental Approvals.
Carefully remove the SGA/A unit from its packing. Check that the unit is complete and undamaged.
The SGA/A & SGA/D units can operated in any industrial environment providing the following limits are not
exceeded
Operating Temperature -10 ºC to +50 ºC
Humidity 95% non condensing
Storage temperature -10 ºC to +50 ºC
While the unit is sealed to IP65 (NEMA 4X) it is advisable to follow the following installation practice where possible
• Minimise vibration.
• Do not mount next to strong electrical fields (transformers, power cables)
• Ensure easy access to interior of the module
• Install electrical protection device, as the unit is not internally fused.
• Always ensure the lid is properly fitted and all 4 screws tightened.
• Always ensure the cable gland is sealing against the cable to maintain the IP (NEMA) rating.
Figure 2.1 Dimensions
5
16
148mm (5 ”)160mm (6 ”)
7
8
Allow for cable entry
80mm
(3⅛”)
at either end
50mm
15
(1 ”)
16
Mounting Holes
Depth
55mm(2.16”)
The 4 screws for the lid are captive and must be tightened to maintain the seal.
The 4.5mm (0.18”) holes for the mounting screws in the base are directly behind the screws for the lid.
The box must not be drilled as this would invalidate the IP rating
Allow sufficient space at both sides for the cable entry.
The Nylon 66 cable glands are designed for ROUND cables.
The waterproof entry and strain relief will seal to a higher rating than the enclosure.
Cable diameter should be between 4mm (0.16”) and 7mm (0.27”)
Mantracourt Electronics Limited SGA/A & SGA/D User Manual
3
Cabling
J 3
J 3
J 1
+
-
Power Connection
Two power supply options are available
SGA/A: 220/230VAC, 50/60Hz
110/120VAC, 50/60Hz
5W Max.
SGA/A & SGA/D: 18-24V DC, 5W (approx. 150mA fully loaded)
NOTE: The SGA/A can be powered from AC or DC sources whichever is available.
It is also possible to connect BOTH AC and DC simultaneously for security of power
supply.
Figure 2.2 Power Connection
220-230 V AC
L L
110 - 120 V AC
18 -24 V DC
N
N
Standard mains 2 or 3 core cable PVC sheathed (unshielded) cable will suffice for the power.
NOTE: Connect the appropriate power to the SGA. For AC powering observe the correct
transformer jumper connections as shown in Figure 2.2 above.
(This diagram is also provided inside the lid).
Connections to the SGA/A & SGA/D input/output signal and the power supply are made via 2.5mm² field terminal
connectors.
Cable entry in the cased versions is via glands in the ends of the case.
Mantracourt Electronics Limited SGA/A & SGA/D User Manual
4
Figure 2.3 Input (Sensor) Connections
NOTE: Strain Excite is the Excitation to the transducer.
Strain Input is the Signal from the transducer.
The Ref 5V/2.5V is generated internally and used for calibration
The cable connecting the sensor to the SGA should be shielded.
This typical cable data is provided for information only.
The cable should have 2 x twin twisted cables. Ideally with each pair individually shielded and with an overall
shield.
Table 2.1
Country Supplier Part No Description
UK Farnell 148-539 Individually shielded twisted multipair cable (7/0.25mm)- 2 pair
Tinned copper drain. Individually shielded in polyester tape.
Diameter: 4.19 mm
Impedance: 54 Ohms: Capacitance/m: core to core 115 pF & core to
shield 203 pF
UK Farnell 585-646 Individually shielded twisted multipair cable (7/0.25mm)- 3 pair
Tinned copper drain. Individually shielded in polyester tape.
Diameter: 6.86 mm
Impedance: 62 Ohms: Capacitance/m: core to core 98 pF & core to
shield 180 pF
UK RS 367-533 Braided shielded twisted multipair cable (7/0.2mm)- 1 pair
Miniature- twin -round Diameter: 4.8 mm
Impedance: 62 Ohms: Capacitance/m: core to core 120 pF & core to
shield 210 pF
If possible segregate the signal cable from Power Cables; allow a 1meter (3 feet) distance from such cables.
Do not run signal cables parallel to power cables. Cross such cables at right angles.
The ground connection conductor should have sufficient cross-sectional area to ensure a low impedance path to
attenuate RF interference.
Mantracourt Electronics Limited SGA/A & SGA/D User Manual
5
Output Connections
Two analogue outputs are available from the SGA, proportional DC current and DC voltage.
The ranges available are as follows: -
Output Range
DC voltage ±10V
NB: Maximum Load on voltage ranges is 2mA.
±5V
0 - 10V
0 - 5V
DC current 0 - 20mA NB: Maximum impedance 500R.
4 - 20mA
The DC current support both ‘sink’ and ‘source’ modes of operation.
Two jumpers JP1 & JP2 provide the means of selecting the desired mode.
Figure 2.4 Output Connections
In ‘Sink’ mode the +ve end of the load is connected to the internal +15V supply on the SGA and the -ve end is
connected to the SGA output. The current through the load is ‘sunk’ by the SGA towards ground (0V).
N.B. In this mode neither connection to the output load is electrically common to the load cell.
Select this option by fitting the two jumpers, JP1 and JP2 to the ‘outside’ positions (See Figure 3.2)
In ‘Source’ mode the +ve end of the load is connected to the SGA output and the current is ‘sourced’ by the SGA
output through the load towards ground (0V).
This mode has the advantage that the negative output connection is common to the load cell
‘- Excitation’ terminal.
Select this option by fitting the two jumpers, JP1 and JP2 to the ‘inside’ positions (See Figure 3.2)
See Chapter 3 for switch settings and details of SINK & SOURCE jumpers.
Mantracourt Electronics Limited SGA/A & SGA/D User Manual
6
Chapter 3 Switch Settings
O
utput Option
Switch Positions
e.g. The switches in Figure 3.1 are depicted as ALL ON.
Figure 3.1 Output Settings–Switch 4
Use switch 4 to select the required output and, if
required, the low pass filter and 5V Excitation.
(See Tables 3.1 and 3.2)
Table 3.1 Output Option
Input Range 4-20mA 0 - 20mA 4-20mA 0 - 20mA 0 - 10V 0 - 5V ±10V ±5V
+ Full Scale 20mA 20mA 20mA 20mA 10V 5V 10V 5V
↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑
0 4mA 0mA 12mA 10mA 5V 2.5V 0V 0V
↓
- Full Scale n/a n/a 4mA Note 1 0mA Note 1 0V 0V -10V -5V
N.B. Full scale output on the voltage ranges is achieved with a bi-polar (±) input
Note 1 Negative inputs can be accommodated on the current output ranges by setting the ‘Zero’ switch SW2 to
+50% (Table 3.8) and setting SW1 to twice the required mV/V setting (Table 3.6).
↓ ↓ ↓ ↓ ↓ ↓
Table 3.2 Switch 4
Analogue Output and Excitation Voltage Options - SW4
SW4 1 2 3 4 5 6 7 8
±10V
±5V
0-10V
0-5V
0-20mA X X X
4-20mA X X X 1↑ 1↑ 1↑=Filter in 1↑Filter out 1↑=10V Exc 0↓=5V Exc
Filter out X X X X X
Filter in X X X X X
10V Exc X X X X X
5V Exc X X X X X
Switch settings (0 = Off 1 = On X = Don’t Care)
Important:
Mantracourt Electronics Limited SGA/A & SGA/D User Manual
7
0↓ 0↓ 0↓
0↓ 1↑ 0↓
0↓ 1↑ 1↑
1↑ 1↑ 1↑
Low pass filtering is switched into operation by setting SW4/6 ‘ON’↑ and SW4/7 ‘OFF’↓.
Reverse these settings to bypass the filter.
It should be noted that either one of these switches MUST be on but not BOTH
X X
X X
X X
X X
0↓ 0↓ 1↑=Filter in 1↑Filter out 1↑=10V Exc 0↓=5V Exc
1↑=Filter in 1↑Filter out 1↑=10V Exc 0↓=5V Exc
1↑=Filter in 1↑Filter out 1↑=10V Exc 0↓=5V Exc
1↑=Filter in 1↑Filter out 1↑=10V Exc 0↓=5V Exc
1↑=Filter in 1↑Filter out 1↑=10V Exc 0↓=5V Exc
0↓ 1↑ 1↑=10V Exc 0↓=5V Exc
1↑ 0↓ 1↑=10V Exc 0↓=5V Exc
1↑=Filter in 1↑Filter out 1↑
1↑=Filter in 1↑Filter out 0↓
Loading...