Hydac ETS 3866-2-000-000 Temperature Switch for Separate Probe

Temperature switching from a remote PT 100 probe

The Hydac ETS 3866-2-000-000 (HYDAC part number 909793) is the version of the ETS 3800 for use with a separate temperature probe. Instead of an integrated probe it takes a PT 100 input through a four-pole M12x1 female cable connection, normally from the HYDAC TFP 100 probe, although common PT 100 probes can also be evaluated. The result is a compact four-digit display and switching unit that can sit on a panel while the probe is installed where the temperature actually matters.

The measuring range is -30 to +150 °C depending on the connected probe, with two PNP transistor outputs.

Technical specifications

Why use a remote probe

A separate probe is the better choice when the tank wall is too thin for a G1/2 thread, when the probe must sit in a thermowell, or when the display must be easy to reach while the measuring point is not. HYDAC supplies the matching TFP 100 probe with a nickel-plated brass installation sleeve, rated to 10 bar, as an accessory. Cable length and probe resistance add to the error, so keep the lead short.

Order code

ETS 3 8 X X – X – 000 – 000: the first 6 after 38 selects the female M12x1 cable connection, the second 6 the male M12x1 four-pole output plug, the 2 two switching outputs, and 000 means no integrated probe. Output code 3 gives one switching and one analogue output, 5 two switching and one analogue on a five-pole plug. The datasheet (E 18.328.2) is the USA edition printed in degrees Fahrenheit. Remember to order the probe separately.

Use the screened cable supplied or equivalent, keep it away from power cables, and set the display to the unit used in your maintenance procedures so that alarms are read consistently.

Documents and quotation

The datasheet is attached. Please list the probe type and the length of the cable needed. See also our temperature instrumentation range.

How the ETS 3866-2-000-000 works

A PT 100 probe is a platinum resistance element whose resistance is 100 Ω at 0 °C and rises almost linearly with temperature. The ETS 3866-2-000-000 feeds a small measuring current through the probe connected to its M12×1 female input, measures the resulting voltage, and converts the resistance into a temperature value. That value is shown on the four-digit LED display and compared with the switching points stored in the instrument. When a set point is crossed, the corresponding PNP transistor output switches the supply voltage to the load, for example a relay, a PLC input, a cooler fan contactor or an alarm lamp.

Because the electronics and the probe are separate, the switch housing can be installed where it is easy to read and adjust, while the probe sits deep in a tank, a return line or a gearbox sump. Temperature drift of the electronics caused by the environment is limited to ±0.0085 % FS/°F maximum for both zero point and range.

Switching functions and settings

All settings are grouped in two menus and are entered with the keypad on the front. A programming lock can be set to prevent unauthorised changes. The main functions are:

• Switching point function or window function, selectable per output. In the window function the output is active only while the temperature stays between a lower and an upper value.
• Switching direction N/C or N/O for each output, so an output can act as a fail-safe alarm that drops out on a fault or loss of power.
• Switch-on and switch-off delay adjustable from 0.00 to 99.99 seconds, useful to ignore short temperature excursions.
• Display choice: actual temperature, peak temperature, switching point 1, switching point 2, or display off, with the unit in °C or °F.
• The display turns through 270° and the housing through 340°, so the unit can be read in almost any mounting position.

ETS 3866-2-000-000 selection & ordering guide

On the four-pole output plug of the -2 version, pin 1 is +UB, pin 2 switching output 2, pin 3 0 V and pin 4 switching output 1. If you need a 4 to 20 mA or 0 to 10 V signal to a PLC in addition to the switching contacts, choose output version 3 or 5; the analogue versions need an 18 to 35 V DC supply.

Installation & maintenance

• Connect the probe with the supplied M12×1 male cable connector and the 3 m LIYCY 4 × 0.25 mm² cable. A four-wire connection keeps the lead resistance from shifting the reading.
• Protect the supply: reverse-polarity, over-voltage, override and short-circuit protection are built in, but the total current of both outputs must stay within the rated values.
• Mount the switch away from strong vibration sources where possible; it is rated to 10 g vibration and 50 g shock.
• Check the reading periodically against a reference thermometer, and replace the probe if the reading is unstable or the cable is damaged.

Typical applications in Oman & the GCC

HYDAC designed the ETS 3800 for separate probe use primarily with the TFP 100 probe for tank installation. Typical uses are oil-temperature monitoring of hydraulic power units, switching oil coolers and heaters, over-temperature alarms on gearboxes and lubrication systems, and temperature supervision of test benches. In Oman and the GCC, where ambient temperatures are high for much of the year, reliable cooler control and over-temperature shutdown protect the oil, seals and pumps of hydraulic systems in industry, ports, mining and oil and gas.

Why source from Seven Star LLC

Seven Star LLC supplies HYDAC temperature switches and probes across Oman and the GCC. Request a quote for the ETS 3866-2-000-000 with the matching TFP probe and installation sleeve; our team can help confirm the correct ordering code.