Load Cell Amplifier with Relays Data Port & Display for WeighingLCA20 Base Unit
SKU: LCA20 Base Unit
Description
The LCA20 is a highly versatile digital load cell amplifier designed for both single and multiple load cell weighing applications. It features an easy one-pass calibration and quick setup process, making it ideal for efficient system integration. Equipped with relays, a data port, and a clear display, the LCA20 provides reliable performance across a wide range of weighing and control tasks.
This listing is for the LCA20 Base unit, please contact us for configuration options.
This advanced load cell weight indicator supports local or remote LCD displays, isolated analogue outputs (4–20 mA and 0–10 V), and relay outputs for control or alarm functions—such as crane overload protection or in-flight compensation for silo and bag-filling operations. Digital communication is available via RS232 or RS485 for setup and data exchange, with compatibility for label and ticket printers.
Offering both analogue and digital output options, setpoint control, and display functionality, the LCA20 operates from either AC or DC power and carries IP65 (NEMA 4) environmental protection.
The LCA20 replaces the earlier LCA15 model, delivering enhanced functionality, improved performance, and updated technology. It is supplied in a robust IP65 ABS bulkhead-mounting enclosure, with alternative versions available for DIN rail or PCB mounting (model LCB20).
For PCB integration, see the LCB20 Load Cell Amplifier and Digitiser.
For further details, visit our Load Cell Amplifier Application Guide or watch the LCA20 overview video on YouTube.
The LCA20 can also be paired with the LCI Load Cell Failure Alarm, a continuous monitoring system that detects load cell faults and triggers alarms—enhancing safety, minimising downtime, and reducing on-site maintenance costs.
Product Features & Benefits
- Full digital set–up using PC or keypad
- 3 x configurable digital inputs e.g. for autotare, peak hold and reset
- RS485 and RS232 digital data output for communications and printing
- Measurement speeds of 10 / 80 samples per sec
- Factory calibration in mV/V
- 5 V excitation supports up to 10 x 350 R load cells
- Fully isolated 4-20 mA and 0-10 V analogue outputs
- 6 wire input to compensate for barrier and cable losses
- 2 set points SPCO relay outputs
- Sensitivity from 0.5 to 7.8 mV/V
- 10 pt linearization
- Firmware now supports Mantrabus 1 & 2, MANTRA ASCII 2 & MODBUS RTU
- ROHS Compliant & Environmentally sealed to IP65 / NEMA 4 enclosure dimensions 200 x 120 x 75 mm
- Supplied in IP65 NEMA4 ABS protected case, stainless steel version or DIN Rail option. See also LCB option
- The LCA20 shown in main photo has the transparent lid option (LTL)
Specifications
| Inputs | |
|---|---|
| The input is of the Load Cell/Strain Gauge type. With transducer excitation voltage of 5 volts @ 160mA to drive 10 x 350R bridges | |
| Compensation by ± sense wires for cable and safety barrier losses down to 3V excitation | |
| Load cell sensitivity range 0.5 to 7.8mV/V (2 ranges configured from keypad or communications port) | |
| Initial offset is no greater than ± 0.15mV (15uV/V) which is cancelled during auto calibration | |
| Speed | 10 and 80 Samples Per Second (configured from keypad or communications port) |
| Factory mV/V calibration accuracy | ± 0.05% FSD being typical |
| Drift | ± 2 ppm per degree C @ 2.5 mV/V typical |
| Non Linearity before linearization | 10 pt typical |
| Internal Resolution | 20 bit or 1 part in 1,000,000 |
| Noise Free Resolution @ 10 Hz | 17.5 bit or 1 part in 180,000 |
| Contact inputs | are available for auto tare, print and peak hold reset and are volt free |
| Analogue Outputs | |
| Drive | 4-20 mA up to 1 Kohm and 0-10 volts up to 2 mA |
| Accuracy | ± 0.15% of range, typical |
| Resolution | as for display up to 13 bits / 4.5 digits. Settling time 350 mS to within 1% of step change |
| Isolation | ±130 V RMS or DC max to analogue input or any other port |
| Power Supplies | |
| LS1 | 110 V-120 V AC or 220 / 230 V AC 50-60 Hz 10 W |
| LS3 | 9-32 V DC 10 W isolated |
| Data Retention/Protection | |
| Retention | 20 years for set up values, minimum of 100,000 write cycles |
| Protection of data and function(s) | Watchdog timer giving repeat auto resets. Impending power detection and hold off. Calibration and Toolkit lock feature |
| Other Options & Accessories | |
| 2 Set Points | Output through 5 A 240 V AC SPCO Relays, with a latching option |
| Communications Port | For data transfer or print via :- |
| RS485 | Enabling up to 253 units to be multi dropped |
| RS232 | For 1 to 1 connection and standard printer drive and large displays |
| Printer Operation | By closure of volt free contact or continuous ASCII stream |
| Baud Rates | 2400, 4800, 9600, 19200, 38400, 57600, 76800, 115200 |
| Die Cast Case | Sealed to IP65 / NEMA 4 with external dimensions of 220 x 120 x 80mm max |
| Stainless Steel Case | Sealed to IP65 / NEMA 4 with external dimensions of 224 x 160 x 90mm |
| PCB Only (Eurocard) (LCB20) | 100 x 160 X 57mm for rack or customers enclosure |
| Environmental | |
| Storage Temperature | -20 to +70ºC |
| Operating Temperature | -10 to 50ºC |
| Relative Humidity | 95% maximum non condensing |
| CEÂ Environmental Approvals | European EMC Directive 2004/108/EC, Low Voltage Directive 2006/95/EC |
Dimensions
Product order options
Please read the following before selecting the options for this product:
LCA20 Base Unit – Standard Instrument with 4-20mA/0-10 Analogue Outputs for ABS Case.
Ordering Information- Starting with the base model LCA20Â select the options that you need to configure the device to meet your needs. i.e. LCA20-LC4-LR1-LS3-LP1-LTL
Options |
Code |
|---|---|
| Junction Box Active | JBA |
| Junction Box PCB (only) Active | JPA |
Base Unit |
Code |
| LCA20 | LCA20 |
Comms |
Code |
| RS485/232 Communications (supports MODBUS RTU, ASCII, MANTRABUS 1 & MANTRABUS 2) | LC4 |
Relay |
Code |
| Relay Output Module 2 Set Points (2 x SPCO 5A 240V AC ) | LR1 |
Power Supplies |
Code |
| AC Power Supply 110/120V, or 220/230V AC | LS1 |
| DC Power Supply 9-32V DC | LS3 |
Display |
Code |
| On Board Programmer | LP1 |
| Remote Hand Held Programmer | LP2 |
Extended Mounting |
Code |
| Transparent Plastic Case Lid | LTL |
Accessories |
Code |
| PGM1 Programming Lead (no discount available) | PGM1 |
| Junction Box PCB (only) Passive | JPP |
Downloads
FAQ
| Q | What Protocols are available with the LCA20? |
| A | There are 4 Protocols CP=128 = Mantrabus 1 a hex based protocol. Most popular, easiest to deal with from programming point of view. CP=131 = Mantrabus 2 updated version of Mantrabus1 CP=133 = Mantra ASCII 2 based protocol designed for old teletype machines, looks easier but actually more complicated to programme. CP = 132 Modbus RTU used a lot in PLCs. 3rd Party S/W available. Hex based. Or alternatively set CP=127 and the device will transmit an ASCII string every display update (used for continuous printout to either printer or display. |
| Q | Does stainless steel case for LCA20 have stainless steel glands? |
| A | No plastic PG9 glands. |
| Q | Does the 4-20 mA output on an LCA20 have galvanic separation? |
| A | No but it does have electrical isolation up to ±130V RMS |
| Q | How do you view the live reading on the LCA20 without Auto Tare and having to calibrate again? |
| A | Go to the ‘measurement’ section in the LCA Toolkit. Note the reading in the ‘Tare’ value box and then change the value to zero. Click on the ‘Tare’ button and the unit will display live reading.Alternatively, using the keypad: Go into the menu and pick AT Mnemonic. Note the reading down and then set to zero. Press return and then the unit will display live reading. To reset Auto Tare re enter value in AT Mnemonic screen which you noted down. |
| Q | What is the maximum length of cable we could connect between a LCA20 unit and a load cell unit? |
| A | It would depend on many different factors: The quality of the cable The type of cable Whether it was 4 or 6 core The number of load cells Environment Interference With the best quality of cable in an ideal environment and with little or no interference we have had operating at 200 metres. |
| Q | LCA20 / SMW can they handle tension and compression? |
| A | Yes |
| Q | Is it possible to connect two LCA20s to one load cell? |
| A | How would the scaling of each remain stable in the event of a failure of one or the other ? Can the output of the load cell be connected to both LCAs? With perhaps a resistor network holding the input of the second to a reference ?A: This is done using 6 wire, with the second LCA20 as 5 wire (no “+” excitation). You could have two 6 wire with two blocking diodes (for redundancy). Or a separate power supply and two 5 wires. |
| Q | How do I factory reset a ADP / ADW / LCA20 / SMW? |
| A | Hold down the Scroll and reset key and then power cycle the unit. * All settings will be reset, including calibration. |
| Q | Can I use a laptop to set up the LCA20? |
| A | Yes, by means of the optional PGM1 Programming Cable and the LCA Toolkit. The option to use the LCA20 keypad is also available. |
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