5
3.2 Above ground water sources (flooded suction)
The DynaDrive DD15-35NPT model comes factory set to 60psi to suit boosting
applications, please note for flooded suction and suction lift applications the factory set
pressure will need to be reduced to prevent a dry run situation. Also note the pressure
tank will also require adjustment to 70% of the set pressure.
Installations with flooded suction require a gate valve
so water supply can be turned off for pump removal and
servicing, see figure 3.2. There is no need to install a one-
way check valve in the suction pipeline as there is a one-
way check valve installed in the tee piece immediately on
top of the DynaDrive pump discharge.
3.3 In-ground water sources (eg suction lift from
in ground tank)
Whenever the installation position of the pump is higher
than the lowest water level, a foot valve should be fitted to the end of the
suction pipe, see figure 3.2. Ensure that the foot valve is at least ½ metre
(1⅔ feet) below minimum water level to avoid a vortex of air being drawn
into pipe.
In suction lift installations that have an unreliable foot-valve it may be
preferable to remove the check valve in the DynaDrive discharge tee piece.
Doing so will allow the DynaDrive pressure transducer to “recognise” a loss
of water from a suction line, while the DynaDrive is in standby. Applications
of this nature, with long &/or wide suction lines consist of a considerable
volume of water, ie > 100 litres (26 US gallons) in the suction pipe.
Temperature variations of the water may create fluctuations in the pressure
of the water, falsely triggering the DynaDrive to start/stop. In such as case,
it is worth considering upsizing the pressure tank to help absorb these
pressure fluctuations. If concerned, please consult your Davey representative.
3.4 Spear point installations
When a pump is installed on a spear, or well point, a check valve fitted
immediately on top of the spear point itself, see figure 3.3. Do not install the check
valve at the pump, or at the top of the well. Do not run the pump without water in
it.
In suction lift installations that have an unreliable foot-valve it may be preferable to
remove the check valve in the DynaDrive discharge tee piece. Doing so will allow
the DynaDrive pressure transducer to “recognise” a loss of water from a suction
line, while the DynaDrive is in standby. Applications of this nature, with long &/
or wide suction lines consist of a considerable volume of water, ie > 100 litres (26
US gallons) in the suction pipe. Temperature variations of the water may create
fluctuations in the pressure of the water, falsely triggering the DynaDrive to start/
stop. In such as case, it is worth considering upsizing the pressure tank to help
absorb these pressure fluctuations. If concerned, please consult your Davey
representative.
3.5 Installs with a mains pressure hot water system
ATTENTION: Always ensure hot water systems are installed
in compliance with manufacturers recommendations and in
accordance with all local regulations.
To protect your system from damage caused by back pressure from hot
water systems, see figure 3.5. You should always have installed on the hot
water inlet an approved non-return valve.
Davey Water Products Pty Ltd cannot accept responsibility for loss or
damage resulting from incorrect, or unauthorised installations.
MAINS W
ATER
Figure 3.2
Figure 3.5
> 1m
> 0.5m
Foot valve
(Not Supplied)
Figure 3.3
Check valve
Figure 3.4
Summary of Contents for DynaDrive DD15-35NPT
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