The CRSR^®-101 is essential whenever I.S. barriers are used for powering and monitoring sensors in hazardous areas. The device performs important functions critical to the successful installation of sensors in hazardous areas. Often, when setting up a sensor powered through an I.S. barrier, the sensor is starved for voltage? And, tedious replacement and re-scaling of termination resistors in the monitoring outstation or PLC is necessary to eliminate wasted voltage drops.

Of course, raising the supply voltage is no help, only blowing fuses or overheating the barriers. Placed in fresh air in front of the barrier, (i.e. between the power supply and the barrier) the CRSR can magically change a marginal or non-performing installation into a success story.

The CRSR-101 benefits and features are:

1. Provides short circuit protection for the non-replaceable 1/4A fuses potted inside Rel-Tek and other I.S. safety barriers.
2. Eliminates costly, difficult to obtain, low current fuses.
3. Maximizes barrier throughput voltage by keeping the output voltage on high side of zener tolerances.
4. Switchable 50/85/95/130 mA output current level accommodates a variety of barriers and sensors -- without overload.
5. Terminates 4-20 mA sensor signal with only 23.7 ohms. This eliminates the analog termination resistor (usually 50-250 ohms) from the barrier voltage drop budget.
6. Re-generates a secondary analog signal, faithfully tracking the primary sensor output with 1% accuracy, including linearity.
7. Provides output signal options: switchable for 4-20 mA current loop: 0.2-1 VDC or 1-5 VDC (non-isolated).
8. Has analog driver circuit which compensates for variable external line and termination resistances, e.g. 0-750 ohms.
9. Accepts most common power supply voltages, 12-30 VDC.
10. Small real estate (0.5x1"), replaces a 10mm fuse, single #6 screw attaches at base. Pigtail leads provide simple hookup.
11. Eliminates multiple voltage regulators normally used to protect zener barriers. No more tedious voltage adjustments to make.
12. Improves installation safety by helping maintain proper operation of the sensor throughout its entire scale/range.

You will be pleased with the CRSR-101. This is, indeed, an indispensable addition to your bag of I.S. monitoring tricks. Unit measures 2.5"H x 1"w x 0.5"d and weighs about 2 oz.

 

Product	Code:	Model
Current regulator (50/85/95/130ma)	5.7430xxx	CRxxx
Current Regulator and Signal Regenerator	5.7405	CRSR-101

When properly installed on the fresh air (outby) side of an I.S. barrier, the CRSR-101 in no way effects or impairs the safety of the installation, nor will it invalidate an MSHA I.S. system, barrier or sensor approval. On the contrary, the CRSR-101 improves safety by helping assure proper operation of the I.S. sensor throughout its full scale range. If any questions arise in this regard, please contact a factory service representative.

CRSR-101 DIP Switch Options (Switch "ON" is toward top of unit)
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Output signal mode (referenced to negative supply).

S1 OFF & S2 OFF 4-20 mA output
S1 OFF & S2 ON 1-5 VDC output
S1 ON & S2 OFF 0.2-1 VDC output
S1 ON & S2 ON not used

Regulated current level (into barrier)

S3 OFF & S4 OFF 50 mA (CO/O2/T/DP/RH/smoke)
S3 OFF & S4 ON 85 mA (general use)
S3 ON & S4 OFF 95 mA (methane)
S3 ON & S4 ON 130 mA (air velocity, section alarms, etc)

CRSR is a registered Rel-Tek trademark.