Gorman-Rupp Pumps S8A1-E95 575/3 1429751 and up - Manual (Page 13)

S SERIES PUMPS OM-06258
PAGE B - 5 INSTALLATION
be of the proper size and type to ensure an ade­
quate voltage supply to the pump. Voltage avail­
able at the motor must be within the range indi­
cated in Table B‐3.
To calculate the voltage available at the motor, pro­
ceed as follows:
a. Measure the voltage across the incoming
lines (1 & 2 for single phase, 1 & 2, 2 & 3, and 1
& 3 for three phase) while the pump is oper­
ating at full capacity. Refer to the literature
supplied with the control box for power supply
connections.
b. Next, subtract the motor cable voltage drop
(see Table 4, Pump Power Cable Specifica­
tions).
c. Do not continue to operate the pump if this
voltage is not within the recommended limits.
Obtain the services of a qualified electrician to
determine the correct field wiring size and oth­
er details to ensure an adequate voltage sup­
ply to the pump.
Table B‐3. Pump Voltage Requirements
NOMINAL
VOLTAGE
3 460 420 500
PHASE
MINIMUM
VOLTAGE
MAXIMUM
VOLTAGE
575 3 520 630
Make certain all connections are tight and that
cable entry points are rainproof. Support the cable
weight, if required, to prevent excessive strain on
cable clamps and cable.
Grounding Methods
Electrically ground the installation before connect­
ing the field wiring to the control box. Install a
grounding terminal to the enclosure and connect
it to a properly embedded electrode.
The material used for the electrode must be an ex­
cellent conductor of electricity, such as copper. If
iron or steel is used, it must be galvanized or other­
wise metal plated to resist corrosion. Do not coat
the electrode with any material of poor conductiv­
ity, such as paint or plastic.
The electrode must conform to the recommenda­
tions of N.E.C. ARTICLE 250. Follow all installation
requirements of the N.E.C., and all applicable
codes. See Figure B-3 for some suggested
grounding methods.
ROCK 8 FEET
(2,4 M)
3/4 INCH (19,1
MM) NOMINAL
DIAMETER
(MINIMUM)
3/4 INCH (19,1 MM)
NOMINAL DIAMETER
(MINIMUM) 8 FEET
(2,4 M) LONG
SOIL SOIL SOIL
1/4 INCH (6,4 MM)
STEEL PLATE 2 SQ.
FEET (1858,1 SQ. CM)
SURFACE AREA
(MINIMUM)
a) PLATE ELECTRODE b) DRIVEN ELECTRODE c) BURIED ELECTRODE
Figure B-3. Suggested Grounding Methods
a. Plate Electrode: An iron or steel plate, 1/4
inch (6,4 mm) thick, completely impeded in
the ground. The plate must present a surface
area of at least 2 square feet (1858,1 sq. cm.).
b. Driven Electrode: A rod or pipe, 3/4 inch
(19,1 mm) in diameter minimum, 8 feet (2,4 m)
long, completely driven into the ground.