Gorman-Rupp Pumps VS6A60-B 1321070 thru 1352520 - Manual (Page 14)

OM-06014 ULTRA V SERIES
PAGE B - 7 INSTALLATION
dard 1‐inch NPT fitting, or the Air Release Valve may
be installed in a spool flange between the two dis­
charge check valves.
Connect the valve outlet to a bleed line which
slopes back to the wet well or sump. The bleed line
must be the same size as the outlet opening or
larger, depending on which Air Release Valve is be­
ing used. If piping is used for the bleed line, avoid
the use of elbows whenever possible.
NOTE
For multiple pump installations, it is recommended
that each Air Release Valve be fitted with an inde­
pendent bleeder line directed back to the wet well.
If multiple Air Release Valves are installed in a sys­
tem, do not direct bleeder lines to a common mani­
fold pipe. Contact your Gorman‐Rupp distributor or
the Gorman‐Rupp Company for information about
installation of an Automatic Air Release Valve for
your specific application.
DRIVE ARRANGEMENTS
Special consideration must be given to drive ar­
rangements for staged pumping applications.
Since pump installations are seldom identical, this
section provides some general recommendations
for selecting drive arrangements for staged
pumps. Consult the factory for information regard­
ing your specific application.
Dual Motor Drives
It is recommended that each pump be directly driv­
en by its own electric motor, either through cou­
plings (see Figure 3) or a belt arrangement (see
Figure 4).
Each motor should be independently operated
through a reduced voltage solid state (RVSS) start­
er, a variable frequency drive (VFD) or an adjust­
able speed drive (ASD). In this arrangement, the
motor powering the lower stage pump should be
programmed to start first and “ramp up” to full con­
dition speed, then the second stage pump motor
should start and “ramp up” to full condition speed.
Pump motor shutdown should be programmed in
reverse order, with the second stage pump motor
“ramping down” before shutting off, then the first
stage pump motor “ramping down” and shutting
off. This “ramp up” and “ramp down” configuration
helps reduce inrush current on startup and de­
structive “water hammer” on both startup and shut
down.
Figure 3. Recommended Dual Motor Direct
Drive Arrangement
Figure 4. Recommended Dual Motor Belt
Drive Arrangement
Single Motor Belt Drives
In staged applications where both pumps are belt
driven by a single motor (either through a syncro­
nous [cog] or V‐belt configuration) certain arrange­
ments must be used in order to ensure proper op­
eration.