The article for this month will be about how to handle the failure of the water
pump supplies coolant to the still and refrigeration condensers and in many
cases the solvent
cooler of the drycleaning machine.
In order to cool these components, a liquid called “coolant” is forced through the coils of the
condensers by a pump.
In systems using a water tower,
the coolant is water; in systems
using a chiller it is either water or a
mixture of water and anti-freeze
In water tower installations, the
pump is sometimes located on the
roof near the tower or on the floor
near the drycleaning machine; in
chillers the pump is generally inside
the enclosure housing the refrigeration components.
Before we get into managing this species of disaster, a few words about
pumps seldom fail without giving ample warning of an evolving problem.
If the circuit breaker in the electrical panel that controls the pump trips
frequently it is a sure
sign of looming disaster.
If you are not afraid of electricity this would be the time to set the breaker
for the pump in
the off position, remove the protective electrical plate at the rear of the pump
then take a good
look at the wire connections at both the pump.
There is precious little room for the wire connections in the end of the pump
vibrate, causing the screw connections or push on connectors to loosen and
eventually fail; in
many cases this is the problem area.
Using a flashlight, observe if there is any melted insulation, bluing or
discoloration of the wires
or connectors. If so replace them.
If you are not experienced in working with electricity hire an electrician for
Remove the cover to the appropriate breaker panel and switch off the breaker
pump. Make sure screws holding the wires in place are securely tightened down.
flashlight observe if there is any melted insulation, bluing or discoloration of
the wires or circuit
breaker connections or the area where the circuit breaker attaches to the power
busses in the
Another harbinger of doom is frequent pump motor shut down due to the motor
which trips the motors internal protective thermostat.
If this is the case, follow the same steps outlined in the previous paragraph
and in addition
make sure the louvers that allow air to flow through the motor are free of lint,
You can drastically shorten the time this internal thermostat requires to reset
by obtaining a
bag of ice, placing it inside another strong plastic bag and laying it on the
far end of the pump
motor. Remember, this is only a temporary solution.
The following goes for all electrical equipment. Do not use the circuit breakers
as switches to
turn equipment on and off! This practice results in the degrading of the
and sometimes will keep the breaker from tripping at the right current levels.
should have a disconnect close by; use this for switching instead of the
Excessive head pressure
The next pump killer is excessive head pressure. Excessive head pressure could
be caused by
a number of factors (see last month’s article) and will be indicated by a high reading (45 PSI
and above) on the pump outlet pressure gage, if you have one installed.
Also, the sound of the pump starting up will be different under high head
Trying to describe sounds is near impossible but the best way I can is to say
starting, the pump the sound will take longer to even out (sorry, best I could
Causes of this problem often lie in the bypass valve being shut or not
sufficiently opened or
the clogging of strainers going into the drycleaning machinery.
Make a coolant bypass
OK, we’ve done our best to avoid the problem, but what to do when the pump fails so you
continue running the drycleaning machine?
We give the drycleaning machine a “coolant bypass.” You’re going to need two lengths of
garden hose, preferably with an ID of 5/8 - 7/8".
One length needs to reach from a water source like a hose bib outside the plant
or a faucet or
valve inside the plant in order to supply cold water; the other length needs to
through a door or to a toilet, sink or drain in order to remove the water which
through the machine.
In addition, two adapters from the garden hose type fitting to pipe type
fittings will also be
Now let’s take a look at what’s available at the drycleaning machine end.
First, you’ll need to shut the valves going to the water pump on both the supply (high
pressure) and return (low pressure) side to prevent the city water that will be
bypassing the drycleaning machine.
On properly designed and installed cooling water systems, there should be
pressure gages and thermometers as well as other locations where you can break
cooling water supply on the water inlet and outlet sides in order to attach
If not, you will need to open unions, break into the piping, and install tees to
allow the hoses
to be hooked up. If you are in the unenviable situation of having to install
tees, also install hose
bibs (these are the angled valves that you use for connecting garden hoses) and
you will have a
permanent emergency connection for future use.
OK, now we’re all “hooked up” (different meaning today from when I grew up) and ready to
Turn on the water and make sure you’ve got flow through the drycleaning machine when it’s
in the dry cycle (some machines will prevent water flow when not required).
You may not be able to distill and dry at the same time, but at least you can
awaiting a new pump.
All new pump or just parts?
On the subject of new pumps — in many cases there is no need to replace the entire pump
requiring lots of pipe disassembly and reassembly. If you order exactly the same
model pump it
is usually possible to unbolt the motor/impellor side from the raceway/piping
side and just bolt
on the new motor/impellor side onto the old existing raceway/piping side.
The next logical question is, in that case why purchase the entire pump? The
answer is I have
never been able to obtain a completely assembled motor/impellor assembly,
raceway, that’s why!
The illustration for this month shows a really simple and inexpensive method to
pump motor from overheating. Whether you’re currently experiencing overheating problems or
not, it’s well worth it to install this cooling device.