Watson-Marlow MR-Series - Manual (Page 51)

Revision 1.4 / August 2013 Visit our website at www.masosine.com 51
Grounding the pump
All supplied pumps are equipped with a grounding option.
In particular in ex-areas, the pump must be grounded by fixing a grounding cable to the corresponding position (see diagram).
In addition to the grounding of the pump, the motor also needs to be grounded! If the drive is not grounded, the pump aggregate
may not be operated.
Material properties
Plastic parts that are fitted inside the pump react more to temperature changes that stainless steel parts. For this reason, the
specified maximum medium temperature (Tm=100°C), for which the pump is designed, may not be exceeded. If the specified
temperature is exceeded, this may cause a linear expansion and may block single components; this in turn could cause the
pump to fail or could result in damage to parts of the pump. Also, excessive temperatures can accelerate the wear of dynamic
parts and therefore reduce the lifespan of the plastic parts.
Corrosion may occur to the Power Frame of the pump if the paintwork is damaged. Corrosion represents a hazard for the use of
pumps in explosive areas (for measures, see Troubleshooting Chap. 21).
Pressure Conditions
To avoid any over-pressure in the pump as a result of a closed pressure line, a pressure controller must be installed.
Maintenance / Repair
• The Filling of the pump is only permitted outside the explosion aria. Tools that are used should in compliance with
ATEX.
• The pump aggregate always needs to be kept clean of dust with a damp cloth to prevent the dust from smouldering.
• The rinsing channels in the power frame must always be checked for blockages and if necessary cleaned.
Cleaning
Caution! No solvent cleaning agents may be used to clean the pump as this could create an uncontrollable explosive
atmosphere.
Medium to be pumped
Chemicals that are combustible below the temperature 120 degrees Celsius (T4/T=120°C) and Carbon disulphide must not be
pumped.
Coupling
If the pump is used in an explosion-risk area, the pump must only be coupled to the drive by means of an elastic, positive
coupling with ATEX certification, at least corresponding to the supplied pump. Chains, toothed belts, v-belts or similar
equipment which may transmit radial forces on the bearings should not be used.
Drive
Any preceding reduction gears and/or control units must have the corresponding ATEX certification, at least corresponding to
the supplied pump. Combustion engines must never be used!
For operation with a frequency converter, this must either be installed outside the ex-zone, or have the same ATEX certification
corresponding to the delivered pump. In any case the converter must have the properties required for operation in ex-zones, for
example, temperature monitoring, speed limitation, etc.
Grounding