Gorman-Rupp Pumps 81 1/2P47A-E2 3P 801781 and up - Manual (Page 12)

80 SERIES OM-02165
PAGE B - 5 INSTALLATION
DISCHARGE LINES
Siphoning
Do not terminate the discharge line at a level lower
than that of the liquid being pumped unless a si­
phon breaker is used in the line. Otherwise, a si­
phoning action causing damage to the pump
could result.
Valves
A check valve in the discharge line is normally rec­
ommended, but it is not necessary in low dis­
charge head applications.
If a throttling valve is desired in the discharge line,
use a valve as large as the largest pipe to minimize
friction losses. Never install a throttling valve in a
suction line.
With high discharge heads, it is recommended that
a throttling valve and a system check valve be in­
stalled in the discharge line to protect the pump
from excessive shock pressure and reverse rota­
tion when it is stopped.
If the application involves a high discharge
head, gradually close the discharge
throttling valve before stopping the pump.
Bypass Lines
If a system check valve is used due to high dis­
charge head, it may be necessary to vent trapped
air from the top of the pump during the priming
process. This may be accomplished by installing a
bypass line from the top of the pump, back to the
source of liquid. The end of the bypass line must be
submerged. The line must be large enough to pre­
vent clogging, but not so large as to affect pump
discharge capacity.
ELECTRICAL CONNECTIONS
Before connecting the motor to the incoming
power, check that the electrical service available
matches the pump motor requirements stamped
on the motor nameplate.
The electrical power used to operate
this pump is high enough to cause inju­
ry or death. Obtain the services of a qu­
alified electrician to make all electrical
connections.
Do not install and operate a non‐explo­
sion proof motor in an explosive atmo­
sphere. Install, connect, and operate
the motor in accordance with The Na­
tional Electric Code and all local codes.
If there is a conflict between the instruc­
tions in the manual accompanying the
unit and The National Electric Code or
the applicable local code, The National
or local code shall take precedence.
Refer to the following motor data before making
electrical connections.
VOLTAGE PHASE HP Hz RPM F.L. AMPS
230/460 3 60 3450 5.8/2.9
MODEL
81 1/2P47A-E2 3P 2