BRINE TANK LOAD TEST
TESTING AND ADJUSTING
SUBJECT:
Brine Tank Load Test
BUSINESS:
Building Services, Material Handling
PRODUCT:
Generator Sets
BRINE TANK LOAD TEST
The most popular and inexpensive method used to
check generator set power output is the brine tank load
test. This simple test uses a salt water solution for a
resistive load between the terminals of a generator. The
equipment required is relatively easy to acquire and
assemble.
EQUIPMENT REQUIRED
Tank -- Preferable circular because electrodes
should be equidistant from each other and the
walls of the tank. It should be 3 to 5 feet (O.9-
1.5m) deep with at least 2.5 gallons (9.4L) per
kW capacity. A galvanized steel stock tank
works well.
Electrodes -- 1/8" to 1/4" (3 to 6mm) thick sheet
steel with surface area of 1.5 square inches
(10cm2) per kW. The electrodes should be
fitted into slotted wooden or steel frames that will
hold
them
stationary
in
turbulent
water.
Insulation is required between each of the
electrodes and between the electrodes and the
frames to prevent an electrical short. The
electrodes must be positioned equidistant from
each other and the tank walls so that each
generator phase has the same line current.
Salt -- About 0.1 pounds (45g) of very fine salt
per gallon.
Electrical Meters -- Portable tong ammeter and
voltmeter to check current and voltage in each
phase. (Use generator control panel if possible).
Miscellaneous -- Lumber or steel for overhead
framework and electrode frames. Sufficient cord
or cable and pulleys to control electrodes.
Rubber or plastic hose to run make-up water to
tank and to direct overflow away from tank.
OPERATING PROCEDURES
Set up apparatus similar to example pictures.
Raise the electrodes out of the water.
Start the generator set and run it at high idle
until it is warm.
Close the circuit breaker.
Slowly lower the electrodes into the water
making sure each causes the same line current
on each phase.
Operate the unit at one-half load for thirty
minutes. This will warm up the unit and permit
current flow to aid in dissolving the salt.
If the line current does not approach 0.8 of rated
full load current when all electrodes are fully
submerged, add salt to lessen the resistance of
the water. The salt should be added slowly to
allow time for complete dissolving. Watch the
ammeter to ensure readings do not pass
maximum allowable. (If the water is cool when
the salt is added, the salt may dissolve suddenly
when the water begins to boil. This will cause a
rapid increase of line current). Additional water
should be added to replace evaporation loss.
Brine tank load will remain reasonably constant
if the water level is maintained, and the water
does not boil. If the liquid is boiling or flashing
into steam around the electrodes, the load will
not be stable. Severe steam flashing around the
electrodes can cause governor reactions that
may appear to be governor "hunting." The best
results are always obtained with minimum liquid
conductivity (lowest
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