Danfoss 017-523866 RT 200 Pressure Switch 0.2-6 bar

RT 200: a 0.2 to 6 bar industrial pressure switch with a latching maximum-pressure trip

Danfoss 017-523866 is an RT 200 from the RT industrial and marine series. It is built for the plant that needs a straightforward, repeatable pressure trip: a single bellows moves an SPDT snap contact, and in this version the contact stays tripped after the pressure has risen above the set value until someone resets it by hand. That latching behaviour is what makes the code useful as a safety cut-out for compressed air, lubrication or water circuits, where a restart should only follow an inspection.

The range of 0.2 to 6 bar and the fixed differential of 0.25 bar are deliberately narrow, so the trip point stays close to the scale value. The data sheet lists the RT series with high accuracy and repeatability, a long operating life and all major marine approvals, and it quotes a SIL 2 capability according to IEC 61508 for the series.

Technical specifications

How the RT 200 is used on machinery and pump skids

Typical duty is the high-pressure limiter on a small compressor, a lube-oil pressure alarm and a pump discharge trip. With a PS of 22 bar and a 25 bar test pressure the housing leaves generous overpressure margin over the 6 bar range limit, so surges in the line do not damage the bellows. Because the differential is fixed at 0.25 bar there is only one spindle to set, which reduces commissioning error.

A sibling, the RT 200L, adds an adjustable neutral zone for floating control with a variable-speed pump, and the same family includes versions with automatic reset; those carry other code numbers. If you are replacing an installed unit, read the type and code from its nameplate and compare with 017-523866 before ordering.

Mounting and electrical connection

The G 3/8 male thread should be sealed with the flat washer or a suitable compound, and the housing is held on its mounting lugs rather than by the pressure pipe. Wiring enters through the 2 x Pg 13.5 screwed entries; keep conductors within the ranges printed in the installation guide for RT 5, RT 110, RT 112, RT 116, RT 117, RT 121 and RT 200.

The contact rating shown above is for the AC15 and AC1 duties of the SPDT system, so use an auxiliary relay or contactor for larger loads. Seven Star LLC is an independent supplier in Muscat; send this code with the setting and the voltage and we will confirm supply.

Selection checks before choosing 017-523866

Start with the pressure at which the circuit must trip and make sure it sits comfortably inside the 0.2 to 6 bar range rather than at either end. Confirm that a manual reset is really what the process needs: it suits safety cut-outs where an operator should inspect the system before restart, but not control duties that must reset on their own. Check the maximum pressure the line can reach during surges or blocked-valve conditions against the PS value, and compare the load to be switched with the contact ratings in the table. Finally, consider whether the IP54 enclosure is enough for the location or whether the switch should be placed in a sheltered position.

Setting and commissioning the trip point

Set the scale to the required trip value following the Danfoss instructions, then confirm the real trip pressure with a calibrated test gauge or pressure source rather than relying on the scale alone. Raise the pressure slowly, note the value at which the contact changes over, and adjust if necessary. After the trip, reduce the pressure, reset the switch by hand and check that the controlled circuit restarts only when intended. Record the final setting and the test result in the commissioning file, and protect the setting against unauthorised change where site rules require it.

Installation in Oman’s heat, dust and humidity

Pump skids, compressor rooms and water plants in Oman are often hot, dusty and, near the coast, humid and salty. Mount the switch where it is shaded from direct sun and protected from water spray and wash-down, with the cable entries facing downward where practical so water does not run into them. Use glands that suit the cable and keep them tight to hold the IP54 rating. Where pressure pulsations from pumps or compressors are strong, review the Danfoss documentation and the pipework layout so that the bellows and contact are not stressed by constant fluctuation, and keep the pressure line short and supported.

Periodic testing and maintenance

A safety cut-out that never trips in normal service can only be trusted if it is tested. Include the switch in the periodic function-test schedule: raise the pressure to the set value, confirm that it trips and resets correctly, and record the actual trip pressure. Inspect the housing, cable entries and pressure connection for corrosion, leaks or damage, and replace a unit that no longer trips at its setting.

Spare units and replacement planning

Because this switch protects equipment and people, a failed unit should be replaced with the same code number rather than with whatever pressure switch is at hand. Keep the code, range, setting and reset type in the maintenance system, and confirm them against the nameplate when ordering a replacement.

Documents and quotation

The attached file is the Danfoss RT industrial pressure switch data sheet AI555514425055, including the type tables, contact system diagrams and dimensions. See also our pressure instrumentation category, and request a quotation for 017-523866 with the quantity you need.