User's Manual

I.S. part

(blue terminals)

non I.S. part

(grey terminals)

Electrical installation

Page 10

Figure 3 Terminal compartment

Warning

Only open the terminal compartment

cover (rear cover) when the power

is switched off.

Lay-out terminal compartment

The terminal compartment at the rear of the

970 SmartRadar ATi is divided into a

non-intrinsically safe and an intrinsically safe

part. Cable entries are ¾” NPT.

Intrinsically safe cabling may only enter at

the left-hand side cable entry, marked Ex-i

(figure 3).

Non intrinsically safe connections

Mains

Mains cabling : Must be suitable for the 970 SmartRadar ATi power rating and, moreover,

approved for use in hazardous areas.

Communication

Enraf field bus : One twisted pair cable is recommended. R = 200 Ω / line; C = 1 µF.

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Maximum length: 10 km.

Enraf field bus lines may be interchanged. If local regulations allow, mains

and Enraf field bus may share one cable. Mind the isolation voltage of the

cores in the cable; refer to the International Standard IEC 61010-1.

Note:

If a quad cable is used and all four cores are twisted together, use two

opposite cores for Enraf field bus lines and the two others for mains.

RS-232C (option): Cable: maximum length 15 m (50 ft); twisted pairs and shielded.

RS-485 (option): Cable: maximum length 1200 m (3900 ft); twisted pairs and shielded.

HART / : Cable: twisted pair; shielded. Maximum cable length: 1500 m (5000 ft);

analog 4-20 mA C = 40 nF; min. AWG 24 (0.2 mm ).

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(option) Loop supply can be: external (passive) or internal (active).