Hydac HDA 4746-CC-0100-0100-Pd-000 Safety Transmitter

Redundant two-channel pressure signal for safety functions up to PL d

The Hydac HDA 4746-CC-0100-0100-Pd-000 (HYDAC part number 922344) combines two independent sensor elements and two evaluation circuits in one body. Both channels output a 4 to 20 mA signal proportional to the same pressure. A higher-level safety controller compares the two signals; a deviation shows a fault. HYDAC specifies the design for safety functions up to Performance Level d, Category 3 under ISO 13849.

The main applications named in the datasheet are mobile safety-related systems, such as load torque indication or load torque limitation on truck-mounted cranes and working platforms. This code has 0 to 100 bar on both channels.

Technical specifications

How the two channels work

Each channel has its own strain gauge and electronics, so a single fault cannot produce two identical wrong readings. The code allows channel 2 to cover the same range as channel 1 or one pressure step higher, for example 0 to 100 bar on signal 1 and 0 to 160 bar on signal 2. In this variant both are 0 to 100 bar. The safety function itself is implemented in the evaluating controller, which must compare the signals and handle faults.

Code decoding

HDA 4 7 4 X – C C – XXXX – XXXX – Pd – 000: 4 selects the G1/4 A thread with 0.5 mm orifice, 6 the M12x1 four-pole plug (V the Deutsch DT04), the first C signal 1 as 4 to 20 mA on three conductors, the second C signal 2 likewise, 0100 and 0100 the two bar ranges, Pd the PL d Category 3 safety version. Pin 1 is +UB, pin 2 signal 2, pin 3 0 V and pin 4 signal 1 on the M12 plug. Datasheet: E 18.381.1/11.13.

Supplier-side confirmation of the safety documentation is advisable, because the performance level of the whole function depends on the wiring and the evaluating logic as well as on the transmitter.

Functional-safety variants are used where a safety controller reads the signal, so keep the datasheet and its safety manual in the project file. Do not treat the transmitter as certified for a safety integrity level unless your own assessment and the manufacturer documents support that use.

Documents and quotation

The datasheet is attached. Check the full safety concept with your system designer before ordering; the datasheet states only the transmitter data. See also our pressure instrumentation range.

HDA 4746-CC-0100-0100-Pd-000 performance data

The table below adds the accuracy and environmental figures from the HYDAC datasheet for the HDA 4700 version for applications with increased functional safety. They apply to each of the two channels.

How the redundant measurement works

Inside the body of the HDA 4746-CC-0100-0100-Pd-000 are two complete measuring chains. Each consists of its own thin-film sensor element and its own evaluation electronics, and each drives its own three-conductor 4 to 20 mA output. The two outputs therefore represent the same pressure through two independent paths.

The transmitter itself does not decide whether the system is safe. The higher-level controller reads both currents, scales them, and compares them continuously. If they differ by more than the tolerance defined in the safety concept, or if one signal leaves the valid 4 to 20 mA band, the controller treats it as a fault and brings the machine into its safe state. This two-channel structure with diagnostics is what the Category 3 architecture in ISO 13849-1 requires.

Selection & ordering guide

• Range: signal 1 and signal 2 can each be 25, 40, 60, 100, 160, 250, 400 or 600 bar; signal 2 also offers 1000 bar. Signal 2 must be equal to signal 1 or at most one step higher. This variant uses 100 bar on both channels, which simplifies the comparison in the controller.
• Connector: 6 = M12×1 four-pole, V = Deutsch DT04 four-pole. Neither mating connector is supplied. On the DT04 version the pins are 1 +UB, 2 0 V, 3 signal 2, 4 signal 1, which differs from the M12 version.
• Supply and load: 7 to 35 V DC allows a maximum load of 250 Ω per channel; 12 to 35 V DC allows 500 Ω.

Installation & maintenance

• Tighten the G1/4 A port to 20 N·m. The 0.5 mm orifice damps pressure spikes, so do not drill it out.
• Route both signal lines in a way that a single cable damage is detectable by the controller, in line with your safety concept.
• Use an IP 67 or IP 69K rated M12 socket to keep the specified protection on vehicles that are pressure-washed.
• Include periodic checks of the plausibility monitoring in the machine inspection plan, as required by the validation of the safety function.

Typical applications in Oman & the GCC

The datasheet names load torque displays and load torque limitation on truck-mounted cranes and aerial working platforms. Such machines are widely used in construction, oil and gas service, ports and utilities across Oman and the wider GCC, where load moment indicators are part of lifting-equipment inspection regimes. The HDA 4746-CC-0100-0100-Pd-000 suits the boom and outrigger pressure measurement in these systems.

Why source from Seven Star LLC

Seven Star LLC supplies HYDAC functional-safety pressure transmitters across Oman and the GCC. Send the complete code and quantity and request a quote; our team can help confirm the correct ordering code for a different range pair or the DT04 connector version.