| As mentioned previously in the
May/June 1998 Franklin Aid, all Franklin Electric submersible products
are Y2K compatible. This includes submersible motors, control boxes,
Subtrols, all versions of Pumptec, and Franklin's newest product,
CP Water. Franklin Electric has spent considerable time and effort
to ensure we, as a company, are Y2K compatible.
As January 1st, 2000 approaches, more
phone calls asking about alternate energy sources are coming into
the Hotline. Generator sizing is the number one issue and we will
discuss proper sizing in the next edition. However, in this issue
we would like to answer questions regarding alternative power sources.
Battery Back-up:
The popularity of battery back-up systems is increasing due to the
concern for Y2K and because more people are moving to remote areas.
Battery back-up systems are used to provide power where utility
power is unavailable or to provide uninterrupted power during outages.
Battery back-up systems are typically used in conjunction with generators,
photovoltaic cells, windmills and utility power sources. These sources
provide DC power to a battery bank while they operate. When the
power goes off, the batteries switch on. However, since our homes
normally operate on AC power, the first step is an inverter.
The Inverter:
The inverter changes the DC (Direct Current) power from the battery
into AC (Alternating Current) power. The inverter also changes or
boosts the typical 12 volt power from the battery to 120/230 volt
AC power which is normally required for our homes. The inverted/boosted
power can then be used to operate a submersible pumping system.
Sine Waves:
There are typically two types of inverters used to convert this
power. One type is commonly known as a “pure wave” or
“sine wave” inverter. The other is known as a “modified
wave” inverter. The name comes from the type of power wave
created or supplied to the output side of the inverter.
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| Pure
Wave: The figure to the left shows a typical “utility”
supplied sine wave. This is the wave that comes into your house
and is used to operate your electrical appliances. This sine
wave is typically smooth and looks sort of like a roller coaster
ride.
Pure wave inverters duplicate the smooth flowing
sine wave and can be used with today's electronics. This includes
televisions, VCRs, computers, etc. This type of sine wave
can also be used to power Franklin Electric's submersible
motors and control boxes.
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Modified
Wave: The figure to the left shows the output from
a “modified” wave inverter. This looks similar to
a pure sine wave except there are typically on/off steps. This
modified wave generally does not work well with electronics
and can be a problem for Franklin's 2-wire and small Hp 3-wire
motors.
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| Concerns:
Franklin's 2-wire motor utilizes an electronic “Triac actuated,
Bi-metallic” switch, know as a BIAC switch. Franklin's
1 Hp and smaller 3-wire motors also use an electronic “Triac
actuated” switch known as the QD (blue) Relay. Triacs are
electronic switches used to turn off the start winding of the
motor. Because a modified sine wave “steps” instead
of “flows”, there may be incidents were this style
of switch may not work reliably. It is best to only use a pure
wave inverter for 2-wire motors. For 3-wire motors a simple
modification to the control box makes it compatible with a modified
wave inverter.
3-Wire Solution:
Substituting a “voltage” relay into the
3-wire control box allows the system to work with the irregular
sine wave shape. Franklin's voltage relay kits supply the
voltage relay, mounting hardware, jumper wires and instructions
required to make this change. Franklin part 305 102 901 is
the 115 volt kit and 305 102 902 is the 230 volt kit.
Franklin 3-wire systems larger than 1 Hp already
contain the voltage relay and will work with either type of
wave.
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Voltage Relay Kit |
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| Frequently
Asked Questions:
Q “Can
I buy the smaller Hp control boxes with a voltage relay factory
installed?”
A Franklin changed the 1/3 through 1 Hp
control boxes to the QD Relay several years ago. We currently do
not manufacture 1 Hp and smaller control boxes with voltage relays.
Q
“How difficult is the voltage
relay to install?”
A The instruction sheet in the relay kit
is very easy to read and makes the installation simple.
Q
“If the voltage relay is
better in this situation, Why doesn't Franklin offer it as a standard?”
A Franklin uses the QD Relay for several
reasons. The most important is it works better. When a voltage relay
opens its internal connection to turn off the start winding an arc
can occur. This arc occurs when the current tries to maintain its
flow as the contacts open. This is a normal phenomenon with voltage
relays. However as the arc occurs, the contacts wear and can eventually
stick or weld together. When this happens, the motor's start circuit
will not turn off.
With the QD Relay, the start winding is switched
electronically. The “triac” turns the current to the start
winding on and off without arcing. Without arcing, the QD Relay
doesn't wear and is able to cycle more times than a voltage relay.
This has been proven many times during life testing of our product.
Better life makes the QD Relay a better choice.
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