Introduction

The CB-33 isolation transmitter measures the effective values of AC or current (True RMS to DC). The module converts, amplifies, isolates, filters and re-converts the voltage signal to an output current of 4 to 20 mA. These types of transmitters are electrically powered through the same two conductors used to transmit signals, so in practice they are termed two-wire. They are suitable for transmitting signals up to 1200 m to the data acquisition system, industrial PC, PLC or some other measuring system.

 

CB-34 isolation modules protect people and measuring equipment and physically separate them from ecstatic events that may appear on the sensor side or somewhere else within a measuring environment. The module inputs are protected from transients and voltage levels up to 500 Vrms and output to 250 V AC. The transmitters have a very low price and excellent features that meet only in very expensive models.

 

The voltage or current input signal is processed through a pre-amplifier and RMS converter. The signal is then filtered and transmitted through an isolation barrier by an amplitude modulation technique that provides high linearity, stable and reliable characteristics. After isolation, the signal is reconstructed by a fourth-order filter and converted to a standard current or voltage output level. This architecture provides excellent linearity, stable and reliable characteristics and does not require input grounding. The signal demodulator on the output (secondary) side of the module restores the original signal, which is then filtered and converted to a 4 to 20 mA current signal.

 

Attributes

  • Instrumentation accuracy, linearity, repeatability and reliability

  • Input RMS voltage 0 to 400 V or RMS current 0 to 5 A

  • Compatible with standard current transformers

  • Frequency range 45 Hz to 1 kHz (optional 20 kHz)

  • Isolation voltage 1500 Vrms continuously or 4 kV 1 minute

  • Accuracy ± 0.20%

  • 80 dB NMR for 50 Hz

  • 110 dB CMR

  • Double isolation: input - output

  • Output: 4 to 20 mA

  • The input is continuously protected up to 500 V or up to 12 A

  • Power supply of the conditioner from 11 V to 60 V

  • Protection by ANSI / IEEE C37.90.1-1989 specification

  • Mounting on DIN rail

  • The warranty period is 7 years, the service period is 10 years

 


 

CB-33 isolation transmitters and their functional block diagram

 

Characterization

The input circuit provides overvoltage protection up to 500 VAC and protection against transients defined by ANSI / IEEE C37.90.1-1989 documents.  The transmitters have a fifth-line filter, which suppresses 50 Hz  with 80 dB. The power supply of the transmitter is via a two-wire current loop in the range of 11 to 60 V. The power supply module of the circuit has a built-in protection circuit for inverse connection of the supply voltage and circuits that prevent passage of transitions. The module has excellent stability in time and does not require calibration or any maintenance. On the front of the module below the front sticker there are two multi-port trimmers for precise adjustment of the offset and gain. Both values are set before delivery, and the user can overbalance these values according to their needs in the range of ± 10%. Transmitters can be switched on and off from the measuring system without switching off the supply voltage or system shutdown. 

 

Power supply for transmitters

 

For power supply up to 50 transmitters, the CS-PS-48, 48W power supply  (left-hand) is recommended, while the power supply of a number of conditioners should use a CS-24-90 of 90W source, which can, under full load, power up to three times more transmitters, although such a large number of transmitters are recommended to be powered from multiple el. sources. Transmitters do not support the rail T-BUS connector because they are powered through a loop.

 

The CS-PS-48 source operates in a wide voltage range from 85V to 265V AC. Both power sources operate in a wide voltage range from 160V to 265V AC. If the user does not want to use this type of power, it can also use other electrical sources.

 

The PCB of conditioner can be protected, on request, with special lacquer that protects electronic components from moisture, corrosion and other types of contamination, which can significantly extend the life of this product and in terms of long-term measurement accuracy. This conditioned conditioner can be applied in many aggressive environments. For example: on ships or on the seashore, in conditions of aggressive vapors, acid, water and other places with high humidity, etc.

 

Picture to the left: Power supply for CS-24-30 transmitters

 

 

 

Specifications and characteristics

(tipically at 25°C)

 

 

 Parametar CB-33
 Input
 Input range 100 mV to 300 V i 0 to 5 A
 Standard Frequency Range 45 Hz to 1 kHz
 Extended frequency band 1 kHz to 20 kHz
 Input impedance 1 MOhm and  0,01 Ohm for current inputs
 Protection
 Voltage protection for voltage models 500 V peak AC and DC max.
 Current protection for current models continuously 12 Arms max.
 Transients ANSI/IEEE C37.90.1- 1989
 Output
 Output range 4 to 20 mA
 Under range 3 mA
 Overload range 30 mA
 Reverse output polarity Continuously protected
 Kontinualna izlazna zaštita max. 250 Vrms
 Isolation
 Isolation voltage: Input-Output-Power supply Continuous 1500 V
 Breakthrough voltage 4 kV 1 minute
 CMR for 50 Hz  100 dB
 Accuracy  
 Total error including nonlinearity, hysteresis and
 repeatability, from 45 Hz to 1 kHz		  Better than ± 0.25% of range
 From 1 kHz to 20 kHz 0,75
 Changes with temperature 80 ppm
 Subsequent adjustment ±10% offset and gain
 Stability of gain ±80 ppm/°C
 Output noise 100 KHz 3 µArms
 Power and ambience
 NMR 80 dB 50 Hz
 Power loop  11 V to 60 V
 Sensitivity to loop power changes ±0,0005 %/V
 Temperature range (ambient) -40 ÷ 85 °C
 Working range within the specification -40 ÷ 80 °C
 Storage -40 ÷ 85 °C
 Relative Humidity No condensation 0 to 90%
 Immunity EN50082-1, ISM Group 1 Class A
 Rail mounting DIN EN50022 35 x 7,5
 Dimensions of the conditioner L:114 x W:22,5 x H:105

 
 Specifications can be changed
  

Prices and types

 

 Type
 

 RMS input

 Output

Accuracy

Frequency range

Power supply

 1-49

 50-99 

 100+  
CB-33-01 0 to 100 mV  4 to 20 mA 0,1% 45Hz to 1kHz 11 to 60V 140 110 90
CB-33-02  0 to 1 V  4 to 20 mA 0,1% 45Hz to 1kHz 11 to 60V 140 110 90
CB-33-03  0 to 10 V  4 to 20 mA 0,1% 45Hz to 1kHz 11 to 60V 140 110 90
CB-33-04  0 to 150 V  4 to 20 mA 0,1% 45Hz to 1kHz 11 to 60V 140 110 90
CB-33-05 0 to 300 V  4 to 20 mA 0,1% 45Hz to 1kHz 11 to 60V 165 135 110
CB-33-06 0 to 1 A  4 to 20 mA 0,1% 45Hz to 1kHz 11 to 60V 155 125 100
CB-33-07 0 to 5 A  4 to 20 mA 0,1% 45Hz to 1kHz 11 to 60V 165 135 110
CB-33-08 0 to 10 A  4 to 20 mA 0,2% 45Hz to 1kHz 11 to 60V 165 135 110
CB-33-09 0 to 15 A  4 to 20 mA 0,2% 45Hz to 1kHz 11 to 60V 165 135 110

 

Prices are without VAT

  

   Option 1. Transmitters typically have a frequency band of 3 Hz. For a bandwidth of 1 kHz or 10 kHz (-3 dB), the price is 3 € higher.

   Option 2. Commodity-protected transmitters for high-humidity environments have a 10 € higher price.

   Option 3. Transmitters artificially tested with the Burn-in process, 48 hours at 60°C have a 15 € higher price.

   Option 4. Transmitters by special user specification: the first piece is 150 €.

 

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   Back to "Conditioners and transmitters - General"
   Series of CS power supply

 
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