Phoenix Contact MACX MCR-EX-SL-2NAM-RO NAMUR Isolating Amplifier

MACX MCR-EX-SL-2NAM-RO Ex i NAMUR isolating amplifier, 2-channel

The MACX MCR-EX-SL-2NAM-RO (item number 2865476) is an intrinsically safe isolating switch amplifier from the MACX MCR-EX-SL family. It reads NAMUR proximity sensors and mechanical contacts installed in a hazardous area, monitors the field wiring for breaks and short circuits, and passes the switching state across a safe galvanic barrier to a relay output in the safe area. It carries two independent NAMUR channels with one normally open relay contact each, in a single 12.5 mm wide housing. Seven Star LLC supplies the MACX MCR-EX-SL-2NAM-RO in Oman and the GCC as an independent supplier in Muscat, and this page summarises the manufacturer data sheet for engineers preparing an instrumentation RFQ.

What the MACX MCR-EX-SL-2NAM-RO designation means

• MACX MCR: Phoenix Contact signal conditioner family for DIN rail mounting.
• EX-SL: Ex i (intrinsically safe) input, slim housing with power bridging.
• 2NAM-RO: 2NAM-RO: two NAMUR channels with relay outputs (one N/O contact each).
• MACX MCR-EX-SL-2NAM-RO-SP: the push-in connection version of the same device (item 2924087).

MACX MCR-EX-SL-2NAM-RO technical specifications

How the MACX MCR-EX-SL-2NAM-RO processes the NAMUR signal

With two channels in one housing, the MACX MCR-EX-SL-2NAM-RO evaluates each NAMUR loop independently. For every channel it supplies about 8 V, treats a loop current below 1.2 mA as blocked and above 2.1 mA as conductive, and applies less than 0.2 mA of hysteresis between the two states. The line-fault window is the same for both channels: a break is detected below 0.05 to 0.35 mA and a short circuit below 100 to 360 Ω. A fault on one channel is shown by a red flashing LED and drives that channel output high-impedance, and because fault messages can also travel over the DIN rail connector, a single collective fault module can watch an entire row of these devices. DIP switches select the direction of action and enable or disable line fault detection, so each device in a row can be matched to the sensors it serves.

Power and fault bridging with the DIN rail connector

Instead of wiring 24 V to each module, the MACX MCR-EX-SL-2NAM-RO can be supplied through the DIN rail connector (TBUS) from a power and fault signaling module such as the MACX MCR-PTB (2865625) or its push-in variant MACX MCR-PTB-SP (2924184). The same bus can carry the collective fault message. The data sheet also lists the MCR-DP divider plate (1430594), which keeps the intrinsic-safety separation distances when Ex i and non-Ex i modules sit next to each other, and the TC-2D37SUB-ADIO32-2EX-P-UNI termination carrier for connecting 16 two-channel MACX Analog Ex i conditioners to I/O cards with D-SUB connectors.

Where it fits and related types

The MACX MCR-EX-SL-2NAM-RO doubles the channel density of the single-channel MACX MCR-EX-SL-NAM-R (2865434) in the same 12.5 mm width, so a marshalling cabinet with many limit switches needs half as much DIN rail. Its push-in sibling is the MACX MCR-EX-SL-2NAM-RO-SP (2924087). Note that the 2-channel unit has only normally open relay contacts, with behaviour inverted by DIP switch, while the single-channel type has a changeover contact. The 2-channel data sheet also lists a TC-2D37SUB-ADIO32-2EX-P-UNI termination carrier, which is intended for 16 two-channel conditioners and therefore matches this type.

Selection and ordering checklist

• Confirm the sensor type: NAMUR proximity switch (EN 60947-5-6) or a contact, with or without resistor network.
• Check the intrinsic-safety parameters of the field device and cable against U_o, I_o and P_o.
• Decide on screw or push-in connection (MACX MCR-EX-SL-2NAM-RO or MACX MCR-EX-SL-2NAM-RO-SP).
• Decide whether the output is one N/O relay contact per channel and whether the relay ratings fit the downstream load.
• Plan power bridging and fault signaling, and divider plates where Ex i and non-Ex i devices are neighbours.
• Check the SIL requirement and the hardware version stated in the data sheet.

Installation, commissioning and maintenance

Plan the layout of a row of MACX MCR-EX-SL-2NAM-RO modules around the field cable schedule: each module serves two sensors, so a marshalling row of eight modules covers sixteen NAMUR points in about 100 mm of DIN rail. Wire the two intrinsically safe input pairs at the top, keep the relay outputs on the safe-area side, and fit the divider plate wherever a non-Ex i module is adjacent. Before power-up set DIP switches for each channel, then simulate each sensor and watch the yellow LED for that channel. Lift one field wire at a time to prove the line fault message. With the maximum current consumption of 35 mA, supply capacity on the DIN rail bus should be calculated for the whole row.

Typical applications in Oman and the GCC

Two-channel NAMUR modules are chosen when the number of points is large: tank-farm high-level and low-level switches, pump-house running and fault feedback, valve open and closed limit switches on actuated valves, and burner or compressor skids in oil, gas and petrochemical plants. In Oman and the wider GCC these appear in remote instrument enclosures and central marshalling rooms; the -40 to +60 °C ambient rating means the same module can be used in shaded enclosures at sites far from air conditioning, provided that the enclosure keeps out sand and moisture.

Information to send with an RFQ

• Full type designation or item number, and quantity
• Field signal type and range, and whether the device is in a hazardous area (zone, gas group, temperature class)
• Output signal needed (relay, 4-20 mA, voltage) and load
• Supply voltage available and whether DIN rail power bridging is planned
• Required safety integrity level or approvals
• Delivery location and documents needed

Documents and quotation

The manufacturer data sheet for the MACX MCR-EX-SL-2NAM-RO is attached on this page.

Send item number 2865476, quantity and delivery location to Seven Star LLC and request a quotation.