NETZSCH NEMO - Application

NETZSCH Pumps North America, LLC
NETZSCH Pumps North America, LLC Website: www.netzsch.com Tel: +1 610-363-8010
119 Pickering Way Fax: +1 610-363-0971
Exton, PA 19341 Email: npa@netzsch.com
has an overload capacity of the VFD's full load ampere rating times 110% - 120% for one
minute and Heavy Duty; which has an overload capacity of the VFD's full load ampere rating
times 150% for one minute. Typically, constant Hp VFD’s are sold with a Normal duty rating
since the applications don’t call for high starting torque which causes amp draw to spike.
Constant torque VFD’s are usually sold with heavy duty ratings so that they can supply elevated
startup amp draws for high starting torque applications.
Application:
Because while running a progressing cavity pump the torque value required by the pump
is fixed; any reduction in supplied torque as a result of operational speed could cause the pump
to fail. Also, depending on the running speed required, a constant HP VFD may not be capable
of supplying the torque needed for pump startup. This is the reason a Constant Torque VFD
MUST be used to operate a progressing cavity pump.
Brad LaValley / Dan Bachrach
NETZSCH Pumps North America, LLC
Exton, November 2011