www.sitspa.com
TRASCO
®
- User and Maintenance Manual
114.02 - Rev. 2 - 2
nd
March 2020
Approved by: SIT S.p.A.
30
5.8.2 Electrical continuity
TRASCO
®
couplings must be installed and maintained in accordance with the standards and rules of good practice for classified
environments against the risk of explosion due to gases, vapours and dusts.
The electrical continuity between the two metal parts of TRASCO
®
couplings is ensured by the conductivity of the components on which
it is mounted (for example motor-pump).
The electrical resistance, measured between the various metallic parts of the coupling and the point of reference, must be verified at the
time of initial installation and, subsequently, during periodic checks.
CAUTION!
TRASCO
®
couplings must not be insulated from the earth;
ensure that connection of the couplings with the earth is
always guaranteed over time.
5.8.1 Protection devices for couplings in hazardous atmospheres
Protection devices for couplings against unintended contact must be firmly attached.
Couplings for use in hazardous atmospheres must be protected by sturdy guards (if possible, made of stainless steel) against falling
objects. They must be able to be easily opened and the aperture size must not exceed the following limits:
• lateral aperture: 8 mm
• upper aperture: 4 mm
The minimum distance between the mechanical guard and the rotating parts must be equal to 5 mm in all directions.
The guard must be electrically conductive within the range allowed by law and can only be removed after having isolated the machine
from the electrical supply.
Those in aluminium and NBR can be used between the pump and the electric motor only if the magnesium, titanium and zirconium
content is less than 7,5%.