General

The CA-30 family of isolated conditioners amplify, filter, isolate, filter again and convert to a level suitable for connection to the data acquisition system, Industrial PC, PLC or other measuring system.

Isolation conditioners protect people and equipment and galvanic is separated from ground loops and other ecstasy events that can occur on the side of the sensor or somewhere else within a measuring environment. The module input is protected against voltage levels and transients up to 250 Vrms. Insulation voltage is 1,500 Vrms.

The CA-30 conditioner family can be mixed in the same application with other families of isolating conditioners and transmitters. They can be plugged into the measuring system and disconnected from it without turning off the power of the power or system shutdown (Eng. Hot swapable).

The air conditioner input has a specially designed wheel that provides protection against incorrectly connected voltages up to 250V AC and transistors as defined by the ANSI / IEEE C37.90.1-1989 document. An Anti-aliasing pole filter is located in the primary module circuit after which the signal is applied to the chopper level.

There are a large number of models available to users on the page : Prices and models of CA-30.

Atributes Instrumentation accuracy, linearity, repeatability and reliability Available models from 10mV to 1000V input Transformer insulation 1500 Vrms (4 kV 1 minute) Linearity ± 0.01%; Accuracy ± 0.03% 160 dB CMR and 80 dB NMR for 50 Hz Triple insulation: input-output-power supply Input continuously protected from 250 V Output: 0 to 10 V, ± 10 V, 0 to 20 mA and 4 to 20 mA Bipolar current output ± 5 mA, and ± 10 mA The option with suffix R has a 240 V, 6 A relay The power supply of the conditioner is 24V DC or 110/220V AC nominal Easy installation on DIN rail Transient protection according to ANSI / IEEE-C37.90.1-1989 specification The warranty period is 7 years, and the service period is 10 years Very good price-performance ratio

Simplified diagram of CA-30

Characterization

The isolation was realized with a chopper car and a linear micro transformer with an isolation voltage of 1,500 Vrms. Signal transmission uses amplitude modulation techniques that allow high linearity, stable and reliable characteristics. The signal demodulator on the secondary side of the module restores the original signal, which is then led to the fourth-order filter to achieve a low noise level. The signal then passes through a buffer which provides a low output impedance. The output from the module can be voltage or current.

The input side of the module is isolated from the output side of the module and both are isolated in relation to the power supply. Input differential amplifier does not require grounding. On the front of the module below the front bezel there are multi-turn trimmers for precise adjustment of the offset and gain. Both values ​​are factory-set and the user can overbalance them according to their needs within the range of ± 1.5% for offset, or ± 3% for gain.

The internal power supply in the conditioner has a built-in protection circuit that prevents passage of transitions and circuits that continuously protects the conditioner from the inverse power supply voltage.

The module has excellent stability in time and does not require additional calibration or any maintenance. The warranty period is 7 years and the service period is 10 years. It is delivered with a user manual and with a calibration graph

CA-30 with 110 / 220V AC Power supply (option)

 The base version of the CA-30 works with a standard DC power supply of 19 to 30V DC (24V DC nominal). However, if the application requires the mains AC power supply, which is not a rare case, then the user can order a conditioner with the suffix A.

This type of conditioner works with an AC voltage of 85 to 265V or with a DC voltage of 100 to 400V. These two power ranges make the CA-30 applicable in most situations. Some users use these conditioners in an environment that is powered by a 110V battery, or in elevated AC voltage conditions.

On this conditioniner model, there are three terminals for connecting the power supply: L, N and GND (Picture on the left). The L should connect the phase, N to neutral, and GND to the  ground. Grounding, apart from the safety function, has the function of reducing the internal power supply oscillations, so it should be connected in any case. If the DC power supply is used, it must be connected to the L and N connectors (the order is not relevant).

Relay (option)

The family of isolating conditioners CA-30 with suffix R has a built-in relay with a working and quiet contact on the external terminals. The relay can switch on or off to 240V, 6A, and can be set to activate when the input signal is greater than the specified value or when the input signal is less than the set value. There are working and quiet contact on the connector. The relay has a built-in hysteresis control and set value can be fine tuned with a precision multi-port trimmer potentiometer.

The only limitation for this version is that if it is used with 220V power supply (version with suffix A), the relay has only a working contact.

The setting of the relay activation level is performed by the potentiometer on the front of the conditioner. In order to avoid the oscillation of the relay when the input size is the same, the hysteresis is assigned to the device. Hysteresis in the first case, when the relay is activated and when the input is greater than the set value, indicates the size of how much the input size should be smaller than the specified relay activation size for it to be turned off. In the second case, it indicates how much the input size should be to be higher than the set to switch off the relay. Hysteresis can be set to 1% or 5% span with an internal jumper.

If the load is applied to the relay of the inductive character, it is necessary to add the "snubber" from the outside in parallel to the relay contacts. The values ​​of the supply components are calculated, but can also be determined empirically for the given application. Generally, even if the load is applied to the relay of the inductive type, a capacitor of 0.2 uF per line with a 10 Ohm resistor can be used. For optimum performance, the supply wheel must be calculated because this is the best way to optimally extinguish the spark at the relay.

Power supply and T-BUS connector

For the power supply of a smaller number of conditioners up to 20, a CS-24-48 that delivers 48W is recommended (picture on the left), and for greater number of conditioners a CS-24-90 of 90W should be used. Both models can, via the T-BUS connector be connected, directly, without wiring to power the conditioners on the same, or with the extension cable, on different DIN rails in a closed environment. This option raises reliability, greatly reduces the time of replacement of the conditioner and allows the conditioner to be connected or disconnected while the T-BUS is powered up.

Both power supplies work in a wide voltage range: CS-24-90 from 160V to 265V AC, while smaller, CS-24-48 can operate as much as 85V to 265V. If users do not want to use this type of power supply, they can also use other power supplies, but in this case, the power supply must be wired from one conditioner to the other by cables.

Picture on the left: Power supply CS-24-48 for conditioners with T-BUS connector