LS DI NAMUR (Intrinsically Safe) CHARM specifications

Installation notes

The LS DI NAMUR (I.S.) CHARM requires an I.S. CHARM Terminal Block.
The LS DI NAMUR (I.S.) CHARM can sense relay/switch contact closure and supports NAMUR sensors with NAMUR-specified line fault detection levels.
The LS DI NAMUR (I.S.) CHARM supports line fault detection for detecting open or short circuits in field wiring when external line fault resistors are used. To use line fault detection you must:
- Enable line fault detection in the configuration.
- Connect the dry contact to a 18 kΩ resistor in parallel for open circuit detection and a .36 kΩ resistor in series for short circuit detection.

Figure: External line fault detection resistors

Table: LS DI NAMUR (I.S.) CHARM specifications
Item	Specification
Channel type	Intrinsically safe discrete input: 8 VDC, dry contact; supports NAMUR sensors On/Off detection on the + signal
Detection level for On	>2.1 mA
Detection level for Off	<1.2 mA
Channel impedance	1 kΩ ±10%
Wetting voltage	8 VDC ± 1 V
Optional line fault detection levels	Guaranteed short circuit: <100 Ω Guaranteed good status: 360 Ω to 20 kΩ Guaranteed open circuit: >75 kΩ NAMUR sensor compatible
Channel Isolation	Galvanically isolated according to EN 60079-11, voltage peak value 375 V.
Input power requirements	+24 VDC input power: +24 VDC ±10% at 28 mA maximum
CHARM heat dissipation (includes terminal block)	0.57 W

Figure: LS DI NAMUR (I.S.) CHARM wiring diagram