Operational Safety; Electrostatic Charge - Endress+Hauser Proservo NMS5 Operating Instruction

1 Safety instructions
4
1.4

Operational safety

Hazardous area
• Use the explosion proof type for measurement in areas where explosion hazards are present.
• Devices installed in areas having explosion hazards must not be opened when the power is on.
• Strict compliance with installation instructions and - ratings, as directed in this supplementary doc-
umentation, is mandatory.
• Device maintenance and repair is restricted to meet explosion proof regulations.
• Tighten the cable gland firmly.
• Devices employed in areas having explosion hazards should be installed and wired in keeping with
explosion proof regulations.
• Ensure that all personnel are properly qualified.
• Observe the certification requirements as well as national and local regulations.
WARNING
Changes or modifications other than those expressly approved by Endress+Hauser are strictly prohib-
ited. Unauthorized modifications can cause malfunction or damage, resulting in serious injury or
death.
1.5

Electrostatic charge

Mounting with a stilling well is recommended for use in a tank which contains flammable liquid with
conductivity at 10 S/m or less.
-8
In case of installation without a stilling well, allow enough stilling time according to the table below
before lowering the level gauge down to the liquid surface. When a stilling well is used, the stilling time
is shown as in column "<10" in the table below.
Conductivity
(S/cm)
-8
≥10
-12 -8
10 ~10
-14 -12
10 ~10
-14
≤10
Reference: Stilling time (min.)
Liquid volume in tank (m
≤10 10~50
≥1 ≥1
≥2 ≥3
≥4 ≥5
≥10 ≥10
(Japan National Institute of Occupational Safety and Health)
Proservo NMS5
3
)
50~100 ≥5000
≥1 ≥2
≥10 ≥30
≥60 ≥120
≥120 ≥240
Endress+Hauser