Pool Controls Chemigem CM55, Руководство пользователя

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Page 15
SPECIAL CONSIDERATIONS FOR VALVE MODELS
A typical installation of a solenoid valve model Chemigem CM55 is illustrated on the next
page.
It is imperative to fit the Injection Elbow to the inlet (suction) side of the pool pump for
Solenoid Valve installations. The required minimum negative pressure/suction is negative
20 kPa.
In selecting the position for the Injection Elbow on the pool pump inlet pipe, ensure that it is
as near as possible to the pool pump.
Installation Below Pool Water Level
See diagram on page 17
When the pool pump and filter are fitted below the pool water surface level, the suction line
may be under positive pressure even with the pump running. In this case an isolating valve
must be fitted to enable the pump and filter to be serviced.
Fit the Injection Elbow between the isolating valve and the pool pump and close the isolating
valve sufficiently to obtain the required suction so as to allow the unit to operate effectively.
Minimum suction is negative 20kPa when the pool pump is running and the filter is clean.
Methods to obtain improved suction involve using venturi devices or orifice plates. Contact
the supplier of the Chemigem or a qualified pool maintenance technician for information on
these.
If the pool pump is more than one metre below the pool water surface it is essential
to fit Non-Return Valves into the chemical supply tubing to prevent back-flow into the
chemical drums.
Failure to prevent the back-flow into the chemical drums would cause spillage from the
drums, which in turn may result in the two concentrated chemicals mixing together out of the
pool water and producing poisonous chlorine gas. In addition, there is the serious possibility
of personal injury from contact with the chemicals and breathing the fumes.
(Refer to diagram on page 17)
Installation to a Heated Pool
Where solenoid valves are used to dose the pool and one pool pump is required to service
both the pool heating system and the filter, the pool heating plumbing must be bypassed.
This is typically done with a Venturi System which allows chemicals to be injected on the
return (pressure) side of the filtration system.
Note that it is simpler to use peristaltic pumps for these types of installations.