Watson-Marlow 620RA - Manual (Page 5)

ATEX: Watson-Marlow 620RA, 620REA and 620RE4A pumpheads User Manual 5
6 Installation guidelines
Please refer to the standard 620R manual (PB0277) for general installation instruc-
tions.
All ATEX pumpheads include provision for the prevention and dissipation of
electrostatic charge. In order to dissipate electrostatic charge effectively there must
be sufficient electrical contact between the pumphead and the suitably earthed drive.
It is imperative that the 620RA, 620REA and 620RE4A pumpheads are
earthed by connecting the earth terminal on the track (circled in the
photograph below) to earth (usually via a suitable point on the pump drive).
It is possible to check the effectiveness of any earth connection by measuring its
electrical resistance. To ensure reliable dissipation of static the maximum
resistance to earth should not exceed 1 MOhm.
Peristaltic tubing has limited conductivity and so its use should be limited to the length
adjacent to the pumphead. Electrostatic testing and length of tubing limitations have
been used to determine that Watson-Marlow tubing is compliant with a II 2G IIB
rating. Earthed, conductive pipework should be used elsewhere in the system.