4
2 Safety instructions
A qualified electrician must connect the unit� Observe the national and
international regulations for the installation of electrical equipment�
2.1 ATEX units (DI52xA)
Remarks for safe use in hazardous areas: operating instructions (Ex protection
related part) for speed monitors according to EU directive 2014/34/EU annex VIII
(ATEX) group II, equipment category 3D�
If no operating instructions (Ex protection related part) or EC declaration of
conformity are supplied with this product in the language of the EU user country,
these can be requested from your dealer (see delivery note) or manufacturer (see
cover sheet / back)�
The ATEX protection is ensured even without mechanical protection�
3 Functions and features
The compact, non-contact inductive speed monitor detects when a speed drops
below a pre-set value and signals this with a switched output�
3.1 Switching function normally open
Transistor output
LED
green
switched (conducting)
on
rotational speed > SP + Hy and during the start-
up delay
not switched (non conducting) off
rotational speed < SP
SP = switch point
Hy = hysteresis
3.2 Switching function normally closed
Transistor output
LED
green
not switched (non conducting) off
rotational speed > SP + Hy and during the start-
up delay
switched (conducting)
on
rotational speed < SP
SP = switch point
Hy = hysteresis
Switching functions of the units
(→ 8 Technical data)