Hydromatic SKM50A Series User manual

©2008 HYD857 (10/27/08)
OWNER’S MANUAL
Submersible Sewage Pump
Automatic and manual models.
Single phase power only — 115 volt.
SKM50A SERIES
Installation/Operation/Parts
For further operating, installation,
or maintenance assistance:
Call 1-888-957-8677
740 East 9th Street
Ashland, OH 44805
Phone: [phone]
Fax: [phone]
Web Site: http://www.hydromatic.com

Repair Parts 2
8B
8A
18
17
19
2
3
4
5
6
7
7B
7C
8
8B
8C
10
16
9
11
15 13
12
14
12A
PARTS LIST
Ref. No. Part
No. Description Req’d. Numbers
2 Cord, electric (20’) 1 21628B044
3 Cap, motor (stamped) 1 24431C061
4 Screw, machine, hex head, 1/4 x 7/8 6 18475A003
5 Ring, “O”, 5-1/2 x 5-1/4 x 1/8 1 05876A146
6 Wire, jumper 1 09859A800
7 Oil, transformer .2 gal. 24709110000
7B Wire, ground 2 09859A801
7C Screw, tapping SST #10 x 3/8 1 09822A032
8 Housing, with rotor & stator 1 27313C001
8A Rotor & Shaft 1 26166B000
8B Washer, spring wave 5.125 OD x 4.659 ID 1 19331A011
8C Plate, Bearing 1 24661B000
8D Stator only 1 26165B000
Ref. No. Part
No. Description Req’d. Numbers
9 Screw, machine, flat head 4 07597A030
10 Screw, cap, 5/16-18 x 3/4 4 19100A004
11 Seal, type 6; 1/2 shaft 1 21607A015
12 Impeller, thermoplastic 1 26053B000
12A Sealant, Loctite grade 2 1 14550A001
13 Case, volute 1 26054D000
14 Cup, U HUVA 1 22835A009
15 Plate, adapter 1 26052C000
16 Bearing, ball 1/2 open face 1 000650241
17 Capacitor 1 26446A000
18 Cradle, capacitor 1 26298B000
19 Control, 115 volt, 20’, piggy back 1 21813B131

Description and Application 3
General
The pump is available with 115 volt, single phase,
1/2 HP motor. All units are single seal only, available in
automatic or manual with 20' power cords. All power
cords have 115 volt grounded plugs.
These pumps are NOT for use in swimming pools or
fountains.
The pumps are designed for use in residential sewage
applications. These units are designed for handling raw
sewage discharge for residential and light commercial
developments.
Impellers are enclosed two-vane type to handle 2"
spherical solids and are made of engineered thermo-
plastic. The discharge pipe size is 2" NPT for attach-
ment to most all sewage applications.
AIR LOCKING
A pump is said to be air locked if water traps air in the
pump and it cannot get out, thus preventing the pump
from operating.
The pumps have a 1/16" air vent hole in the impeller
chamber to let out trapped air. If this hole becomes
plugged, the pump may air lock. As a secondary precau-
tion a 1/8 hole should be drilled in the discharge pipe
below the check valve. The check valve should be 12 to
18 inches above pump discharge. Do not put check
valve directly into pump discharge opening.
PACKAGING
Each pump is packaged separately in a carton marked
with a catalog number and Hydromatic engineering
number.
LEVEL CONTROLS
All pumps must use sealed level control switches for
automatic operation. All automatic pumps have built-in
level control float switches. The power cord has a
GROUND PIN that plugs into a grounded receptacle.
The grounded receptacle cannot be used in the wet
sump or basin due to DANGER of current leakage.
On all duplex units or simplex installations with addi-
tional options like high water alarm, the power cord
plug must be cut off and wired into a control panel or
into a sealed junction box if used in wet sump or basin.
The pump has a mercury-free, 115 volt mechanical
piggy-back float switch, available in 20' lengths. The
switch is provided with a cable tie to be mounted to the
discharge pipe, tethering the cable. Plug the switch cord
plug into a 115 volt, properly grounded outlet. Plug the
power cord into the back of the switch cord and tape
the cords to the discharge pipe every 12".
MOTOR TYPE
The motors used in the pumps are pressed into the cast
iron housing and surrounded by dielectric oil for the
greatest heat dissipation. The pump uses a permanent
split capacitor, 1/2 HP, 1625 RPM motor. The unit has
Class A motor insulation, and is available in single
phase, 115 volt with overload protection and uses a
lower ball bearing - upper sleeve bearing. The pump has
no starting switches and does not require a control
panel for simplex installation.
SAFETY WARNINGS
Risk of electric shock. Pumps are supplied
with a grounding conductor and grounding-type attach-
ment plug on the power cord. To reduce the risk of elec-
tric shock, be certain that it is connected only to a prop-
erly grounded, grounding-type receptacle. DO NOT cut
off ground pin or use an adapter fitting. DO NOT use an
extension cord with this pump. Entire plug may be cut
off if a control panel is used.
When wiring this pump, follow all local electrical and
safety codes and ordinances as well as the most recent
National Electric Code (NEC-ANSI/NFPA 70).
All pumps have a GROUND WIRE that is connected to
the motor. This wire goes to the receptacle or control
panel which must be connected to a good outside
GROUND such as a metal water pipe or GROUND
STAKE DRIVEN AT LEAST 8 feet into the ground.
INSTALLATION
Basin or tank must be vented in accor-
dance with local plumbing codes. These pumps are not
designed for and MUST NOT be installed in locations
classified as hazardous in accordance with the National
Electric Code ANSI/NFPA 70.
Catalog Cord
No. HP V Ph Length Type
SKM50A 1/2 115 1 20’ Auto

LIMITED WARRANTY
HYDROMATIC warrants to the original consumer purchaser (“Purchaser” or “You”) of HYDROMATIC products
that they will be free from defects in material and workmanship for the Warranty Period of (whichever occurs
first): 12 months from date of original installation, or 36 months from date of manufacture.
Our warranty will not apply to any product that, in our sole judgement, has been subject to negligence, misap-
plication, improper installation, or improper maintenance. Without limiting the foregoing, operating a three
phase motor with single phase power through a phase converter will void the warranty. Note also that
three phase motors must be protected by three-leg, ambient compensated, extra-quick trip overload relays of
the recommended size or the warranty is void.
Your only remedy, and HYDROMATIC’s only duty, is that HYDROMATIC repair or replace defective products
(at HYDROMATIC’s choice). You must pay all labor and shipping charges associated with this warranty and
must request warranty service through the installing dealer as soon as a problem is discovered. No request
for service will be accepted if received after the Warranty Period has expired. This warranty is not transferable.
HYDROMATIC SHALL NOT BE LIABLE FOR ANY CONSEQUENTIAL, INCIDENTAL, OR CONTINGENT
DAMAGES WHATSOEVER.
THE FOREGOING WARRANTIES ARE EXCLUSIVE AND IN LIEU OF ALL OTHER EXPRESS AND
IMPLIED WARRANTIES, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE FOREGOING WARRANTIES
SHALL NOT EXTEND BEYOND THE DURATION EXPRESSLY PROVIDED HEREIN.
Some states do not allow the exclusion or limitation of incidental or consequential damages or limitations on
the duration of an implied warranty, so the above limitations or exclusions may not apply to You. This warranty
gives You specific legal rights and You may also have other rights which vary from state to state.
This warranty supersedes and replaces all previous warranty publications.
HYDROMATIC
740 East 9th Street, Ashland, OH 44805
Phone: [phone] • Fax: [phone] • Web Site: http://www.hydromatic.com
Risk of asphyxiation or poisoning. Never
enter pump chamber after sewage or effluent has been
in basin. Sewage water can give off methane, hydrogen
sulfide, and other gases which are highly poisonous. For
this reason, we recommend installing effluent pumps
with a quick removal system. The quick removal system
may be a union or Cam-lok® coupling if the pipe or
discharge hose is within reach from the surface, or a rail
system type quick disconnect on deeper installations.
See installation drawings for suggested installation.
The dosing tank or pumping chamber must be
constructed of corrosion resistant materials and must be
capable of withstanding all anticipated internal and
external loads. It also must not allow infiltration or exfil-
tration. The tank must have provisions for anti-buoy-
ancy. Access holes or covers must be adequate size and
be accessible from the surface to allow for installation
and maintenance of the system. Access covers must be
lockable or heavy enough to prevent easy access by
unauthorized personnel. The pumping chamber holding
capacity should be selected to allow for emergency
conditions.
The discharge pipe must be the same size as the pump
discharge, 2" or larger. In order to insure sufficient fluid
velocity to prevent any residual solids from collecting in
the discharge pipe, it is recommended that a minimum
flow of 2' per second be maintained. (21 GPM through
2" pipe and 46 GPM through 3" pipe). It is recom-
mended that PVC or equal pipe is used for corrosion
resistance. A full flow (ball or gate) shut-off valve must
be installed to prevent back flow of effluent if the pump
must be removed for service. A check valve must be
installed on pressure sewer systems and on other
systems (where conditions allow) to prevent back flow
and to reduce wear on the pump system.
A high water alarm must be installed on a separate
circuit from the pump circuit. The alarm should have
the ability to be tested for proper operation.
Installation 4

Installation 5
30” DIAMETER SIMPLEX

Maintenance 6
BEFORE DISMANTLING PUMP FOR
REPLACEMENT OF PARTS
Clean pump thoroughly. Knock off all scale and
deposits. Submerge complete unit in Clorox solution for
one hour before taking apart. Wear rubber gloves.
TO REPLACE POWER CORD OR
AUTOMATIC CONTROL FLOAT
1. Use a wrench to loosen and remove thermoplastic
nut from the cap socket. Use your fingers to pull and
wiggle the cord end connector from the socket.
2. To replace either the power cord or automatic
control float, align the half circle notch on the cord
end connector with the half circle key in the socket.
Press the connector into the socket all the way.
3. Slide the thermoplastic washer onto the top of the
cord end connector.
4. Screw the thermoplastic nut into the socket. Tighten
the nut snugly, but do not over tighten. The nut may
be tightened a little more after the connector has set
over a period of time.
5. If replacing automatic control float be sure to tether
float approximately 3-5/8".
FOR SHAFT SEAL ONLY REPLACEMENT
1. Remove the six screws from top thermoplastic cap
and bump cap with plastic hammer to loosen.
2. Lay the cap back, do not disconnect wires from the
cap. Pour all the oil from the pump. If the old seal
failed there may be water in the oil and old oil
should be discarded.
3. Remove the four hex head machine screws holding
the volute to the adapter plate and lift motor
housing and impeller out of volute.
4. Lay pump on its side. Place a flat screwdriver in the
slot in the bottom of the shaft and turn the impeller
counterclockwise to remove it from the shaft. A
blow from a rubber hammer may be necessary to
loosen the impeller.
5. Remove the rotating portion (carbon) of the seal
with pliers. Pry out the stationary portion (ceramic)
with a pair of slotted screwdrivers to remove from
volute casing. Discard the old seal assembly parts.
NEVER USE OLD SEAL PARTS; REBUILD PUMP
WITH ONLY NEW SEAL ASSEMBLY.
6. Thoroughly clean the shaft and volute casing with a
clean cloth. If the drained oil showed signs of water,
then the motor should be air dried for several days
to remove any remaining moisture.
7. Remove the seal from the package being careful not
to touch the carbon or ceramic faces with fingers or
anything dirty. Add a film of oil to the perimeter of
the rubber cup holding the ceramic and insert into
the motor housing. Use a push tool the same size
as the ceramic face (a short piece of PVC pipe
works well).
8. With a clean dry cloth, wipe away any smudging or
oil from the seal faces. Add a film of new oil onto
the motor shaft. With the carbon facing towards the
ceramic, slide the rotating part onto the motor shaft.
Push it on far enough to attach impeller.
NOTICE: Be sure you do not nick, scratch or
damage the seal face.
9. Screw the impeller clockwise onto the shaft using a
screwdriver to hold the shaft from turning and
tighten impeller. Use Loctite or equal on shaft
threads.
10. Check HUVA cup seal in volute case inlet. If worn,
replace.
11. Place pump upright on top of volute. Be sure mating
parts are together and reassemble the four machine
screws and tighten.
12. Check that the impeller turns freely.
13. Replace oil in motor housing using only Hydromatic
submersible transformer oil. The oil should be about
1/2" above the upper surface of the bearing plate.
14. Reinstall the top thermoplastic cap, making sure the
o-ring is in position on the cap. Tighten the top six
screws snug, but do not overtighten.
15. Plug pump into receptacle to test operation. Pump
must run quiet and free of vibration.
TO REPLACE MOTOR STATOR
HOUSING ASSEMBLY AND SEAL
1. Stator assembly includes housing, stator, rotor with
shaft, ball bearing and metal bearing plate. (See
repair parts list)
2. Remove the six screws from top thermoplastic cap
and bump cap with plastic hammer to loosen.
3. Disconnect the four motor lead wires from the cap
pin terminals and remove cap. Pour all the oil from
the pump.
4. Remove the four machine screws holding the volute
to the adapter plate.
5. Lay pump on its side. Place a flat screwdriver in the
slot in the bottom of the shaft and turn the impeller
counterclockwise to remove it from the shaft. A
blow from a rubber hammer may be necessary to
loosen the impeller. Discard old seal part.
6. To assemble the new ceramic seal seat into your
new stator housing assembly, clean the seat cavity
thoroughly and follow Steps 7 & 8 “For Shaft Seal
Only Replacement”. NEVER USE OLD SEAL PARTS.
USE ONLY COMPLETELY NEW SEALS.
7. Screw the impeller clockwise onto the shaft using a
screwdriver to hold the shaft from turning and
tighten impeller. Use Loctite or equal on shaft
threads.

Maintenance 7
8. Make sure the shaft surface is clean and lightly
oiled. Press by hand the rotating half of the shaft
seal onto the shaft. Be sure the rotating carbon
washer is positioned adjacent to the ceramic seat.
9. Assemble the volute to housing with the four hex
head screws. Position discharge the same as before
in relation to switch clamp.
10. Check HUVA cup seal in volute case inlet. If worn,
replace.
11. Check that the impeller turns freely.
12. Guide the four motor wires up through a common
hole in the bearing plate and place the protective
plastic tube over the four motor wires.
13. Position the o-ring into cap and reconnect the four
motor wires as shown in wiring diagram. The two
green ground wires connect to the pins nearest the
‘G’ marked on the cap.
14. Put oil in the motor housing using only Hydromatic
submersible transformer oil, Part No. 24709110000.
The oil should be about 1/2" above the surface of
the bearing plate
15. Reinstall the top thermoplastic cap, making sure the
o-ring is in position on the cap. Tighten the top six
screws snug, but do not overtighten.
16. Be sure the 1/8" NPT pipe plug is in the top cap.
17. Plug pump into receptacle to test operation. Pump
must run quiet and free of vibration.
NOTE: When replacing top cap with a new one, be sure
the jumper wire and pipe plug are in place. See wiring
diagram. Tether level control to motor housing with float
extended 3-5/8" to 4".
Winding Locked
Resistance Max. Rotor
HP Speed V Ph in Ohms Amps Amps
1/2 1625 115 1 2.0 9.0 17.6
MOTOR RESISTANCE CHART
WIRING DIAGRAM
PROBABLE CAUSE
1. Check for blown fuse or tripped circuit breaker.
2. Check for defective level switch.
3. Where control panel is used be sure H-0-A switch is in the AUTO position. If it
does not run, turn switch to the HAND position and if the pump runs then the
trouble is in the automatic electrical system. Have ELECTRICIAN make elec-
trical checks.
4. Check for burned out motor. Occasionally lightning can damage a motor even
with lightning protection.
5. Where plug-in cords are used be sure contact blades are clean and making
good contact. DO NOT USE PLUG-IN CORDS INSIDE A SUMP OR WET
WELL.
6. Level control ball or weight may be stuck on side of basin. Be sure it floats
freely.
1. Check for air lock. Start and stop pump several times, if this does not help it
may be necessary to loosen a union in the discharge line to relieve air lock.
2. Check valve may be installed backwards. Check flow arrow on valve body.
Check shut-off valve. It may be closed.
3. Check vertical elevation. It may be higher than pump can lift. (See pump
curve.)
4. Pump inlet may be plugged. Remove pump to check.
CONDITION
Pump does not run or start when water is
up in tank.
Pump runs but does not deliver flow
Risk of electrical shock. ALWAYS UNPLUG POWER CORDS OR TURN OFF ALL MAIN AND BRANCH CIRCUIT
BREAKERS BEFORE DOING ANY WORK ON THE PUMP. If control panel is remote from pump, disconnect lead wires to motor
so that no one can turn the circuit breaker back on.
TROUBLESHOOTING
Plug Side for
Piggy-Back Switch
Power Cord
Side
Name Plate
Surface
Black Jumper
Motor
(Black)
Motor
(Black)
Motor
(Green)
Motor
(Green)
5893 1008

Dimensions and Performance 8