sequence pumps

[Russell Peters]

THHN is single strand copper wire wrapped in a plastic coating to insulate it.

[Steve E]

I have a different take on the use of extension cords than most folks out there and about. For a run of 50 feet or less I use an extension cord of 12 ga. wire. For runs over 50 feet up to 100 feet I use an extension cord of 10 ga. wire. I get my cords from an outfit called Western Tool and Supply. The cords are reasonable in cost.

My reasoning behind these sizes is voltage drop. Voltage will drop over distance and is related to the size of the wire. I agree with Russ on the use of conduit and the appropriate wire size. I personally do not like to use 14 ga. or 16 ga. extension cords.

As far as restricting the flow of a pump, if you need to do so then do it on the discharge side of the pump. There is less harm to the pump this way. Centrifigal pumps like the sequence will "slip" the water that is not discharge immediately.

Steve

[Rich L]

Most codes and certainly OSHA require an outlet within 6' of the pump. If not, you must have a switch nearby to act as an emergency disconnect. Inside or outside permanent extension cords are not allowed by OSHA for good reason. Some of them were mentioned earlier.

For long runs I usually trench and direct bury. Shorter, conduit at 12" unless I run it above ground.

It isn't all that expensive to have an electrical contractor come in and install a GFCI outlet near the pump and you will be safe. And then again, you can have some other outlets and lights instaled too.

[junglegeorge12]

Quote: Originally Posted by reptar15 c) if i need to make a housing for the pump, do i need to keep the pump 100% dry? would some moisture destroy the pump? d) how effective are the leaf traps/priming pots? e) if i restrict the flow going OUT of the pump, would it do any long term harm? thanks

leaf traps will keep your impellers clean which is important to keeping the bearings good, and the full force of flow going.

To question 'e' the categoric answer is YES. Restricting flow harms pumps. Why do it? Just add a water feature and enjoy. Or make a valved bypass loop so you can control flow.

[Rich L]

Hi Jungle,

Actually the centrifugal pumps need some restriction to operate in their most efficient range. The restriction can be normal head or simply a partially closed valve.

These pumps are designed to operate reliably over the entire range of their design curv, and some. In the passed, the pumps were designed to be operated within the curve but hobbyists were often trying to lower head and move more water to a point the motors were overheating. Not the problem with the design, just the installation, They now overrate the motors we use. This allows us to operate with very little head, but it's extremely inefficient use of power.

[junglegeorge12]

Any significant restristion can destroy the pump or greatly shorten it's life. All centrifugal pumps have all the restriction they need to operate in their highest efficiency range built into them, it is called the outlet hole. Further restriction can cause over amping and impeller vibrations, slippage- sudden slippage due to restrictions causes the motor to spin faster then it suddenly gets hit with a load when it stops slipping...that will wear a motor out quickly. Restrict one real good and put an accurate amprobe on it and watch and listen.

Sequence pumps are designed to operate with low heads and high volume. The impeller and wet end design determines how efficiently it operates at different heads, not the motor size.

[Rich L]

Way off base George.

[junglegeorge12]

Sorry to disappoint you Rich, but you are wrong.

[luke frisbee]

JG
just don't disappoint a poor koi hobbyist in Florida
His address is

Luke Frisbee
334 first ave
Indialantic, FL 32903

[bekko]

Rich L, why is running with very low head an inefficient use of power? You are getting the most flow for the kwh.

-steveh opkin