4.11 Automatic Contr ol For Full-Tank Shutoff
THIS DOES NOT APPLY TO SWIMMING POOL APPLICATIONS
This section applies to water transfer systems that use
SunCentric
P
to fill a storage tank.
We recommend the use of a float switch or other means to
prevent overflow of the storage tank. This will stop the pump
when the tank is full, then reset when the level drops. This
conserves ground water, prevents overflow, and eliminates
unnecessary pump wear.
ETAPUMP
controllers allow the use of
small signal cable to a remote float switch, even if the tank is a
long distance away.
Float switch requirements
1. A switch must be used, not wet electrodes.
2. It must not be allowed to switch on/off rapidly.
3. The preferred system requires a float switch to MAKE contact on rise to turn the pump OFF (reverse
action).
Float Switch Kit
from Dankoff Solar (Item # 10320) meets these requirements. Obtain it from your
ETAPUMP
supplier. The kit includes a sealed float switch (non-mercury type), cable weight and cable
clamp as illustrated.
Float switch cable requirements
1. Two wires are needed.
2. Minimum wire size #18 AWG
3. The cable must be suitable for its environment.
4. If it must run a long distance, use twisted-pair shielded cable to reduce the chance of damage from
lightning-induced surge. (See Section 4.2, Grounding and Lightning Protection).
Float Switch Cable
from Dankoff Solar Products (Item #10326) meets these requirements. It is approved
for sun exposure and direct burial, has a twisted pair and a metallic shield for surge resistance.
Wiring to the junction box
The controller (and junction box) offers two options for connection of a
remote switch. These allow the use of either a “normally open” (N.O.) or a “normally closed” (N.C.)
switch. “Normal” refers to the status of the contacts when the switch is DOWN and is calling for water.
When using a NOswitch, the NC terminals (4 and 5) must be wired together. Connection of a standard
on/off switch to these terminals will turn the pump on/off in the normal, logical manner.
Wiring the
Dankoff Solar Float Switch Kit
(Item #10320
) This is a “normally open switch”. Connect it
to terminals 3 and 4 (NO) and common) and connect terminals 4 and 5 together, as illustrated. When the
switch floats up, it MAKES contact, and the pump stops. This is called “reverse action”.
ILLUSTRATION
Connection of
Dankoff Float Switch Kit
(NORMALLY OPEN) to junction box terminals
UP (closed)
FLOAT SWITCH
(normally open)
DOWN (open)
If cable is shielded,
ground this end only
OFF
ON
sealed
cable clamp
cable
weight
pumping
range
WATER
STORAGE
TANK
FLOAT
SWITCH
NO 3
Common 4
NC 5
Remote
Float
Switch
Summary of Contents for SunCentric P
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