NBB20-U1-E0

What type of sensor is this and what does it detect?

It is an inductive proximity sensor designed to detect metal targets without physical contact. It responds to conductive materials (such as steel, stainless steel, aluminium, brass and copper) by generating an output signal when a target enters the sensing zone.

What is the nominal sensing distance?

The rated operating distance is 20 mm when used with a standard ferrous (mild steel) target and installed flush. In practice, the actual operating distance is typically 18–22 mm (typ. 20 mm), with an assured operating distance of 0–16.2 mm.

What does 'flush installation' mean for this sensor?

Flush (also called embedded) installation means the sensor can be mounted level with, or within, metal surroundings without excessive influence on its sensing behaviour—provided the installation follows normal flush-mounting rules for inductive sensors.

How does the output behave (NO/NC) and what is the output type?

The switching function is normally open (NO), and the output type is NPN (3-wire DC). When a target is detected, the output switches on in the NO sense.

What supply voltage is required?

It operates on 10–30 V DC.

What is the maximum load current the output can switch?

The output can switch up to 200 mA (operating current IL 0–200 mA).

How fast can it switch (switching frequency)?

The switching frequency is up to 440 Hz, making it suitable for many counting and position-detection tasks where rapid response is needed.

Does it have protection features for wiring faults?

Yes. It includes reverse polarity protection and pulsing short-circuit protection, which helps protect the sensor against common wiring and load faults.

What are the electrical connection details?

It uses screw terminals and is a 3-wire DC device. The typical terminal assignment is: 1 = L+ (positive supply), 3 = L- (0 V), 4 = switching output. Up to two conductors with the same cross-section may be fitted per terminal.

What conductor sizes can be used with the screw terminals?

Core cross-section is supported up to 2.5 mm². Minimum is 0.5 mm² without wire end ferrules (or 0.34 mm² with connector sleeves). Maximum is 2.5 mm² without ferrules (or 1.5 mm² with connector sleeves).

What do the LED indicators show?

It has four LEDs arranged for 360° visibility. Green indicates operating voltage present, and yellow indicates the switching state (target detected/output active).

Is the sensing distance the same for all metals?

No. Like most inductive sensors, sensing distance is reduced for non-ferrous metals. Typical reduction factors are: aluminium 0.33, copper 0.31, stainless steel (304) 0.74, brass 0.41 (relative to mild steel at factor 1.0).

What environmental protection rating does it have?

It is rated IP68 / IP69K, meaning it is well suited to demanding industrial environments where high ingress protection is required.

What ambient temperature range can it operate in?

The ambient operating temperature range is -25 to +85 °C.

Is there a start-up delay after power is applied?

Yes. The time delay before availability is approximately 80 ms.

What are the key physical characteristics?

The housing uses PA/metal with an epoxy powder coating, with a PA sensing face and a plastic housing base. Typical dimensions are 118 mm length, 40 mm height, 40 mm width, with a mass of approximately 225 g.