Black Box To Turn On a Pump

[cb]

I have a swimming pool pump that I'd like to turn on if either one (or both)
of two conditions exist:

Presently the pump's power cord can be plugged into either a clock/timer so
it will turn on at certain times of the day that I choose,

OR

The pump's 240vac power cord can be plugged into a socket attached to a
'computer' on a solar heating system, and that socket will be turned on when
the computer decides the solar panel temperature is not hot enough to heat
the pool water. This allows a gas heater to turn on and heat the pool.

I would like to have the pump turn on if either one (or both) of the
conditions exist, but I need some advice. What I envision is that the pump
power cord will be plugged into some kind of back box containing a couple of
relays. The black box will have two inputs, one from the clock/timer and
the other from the solar computer. It either (or both) of the inputs has
voltage, the output to the pump power cord will have voltage. If neither
has voltage, there would be no voltage to the pump power cord.

I have the pump (750 watt), the clock/timer, and the solar computer. I need
to build the black box.

I suspect this is not rocket science but choosing and connecting the relays
is beyond me. I'd welcome any advice.

Please let me now if this is unclear and I will elaborate.

Thanks,
Clark
(in Melbourne, Australia)

 

[Ross Herbert]

On Thu, 24 Feb 2005 11:50:31 +1100, "cb" <clarkb@nospamplease.com>
wrote:

I have a swimming pool pump that I'd like to turn on if either one (or both)
of two conditions exist:

Presently the pump's power cord can be plugged into either a clock/timer so
it will turn on at certain times of the day that I choose,

OR

The pump's 240vac power cord can be plugged into a socket attached to a
'computer' on a solar heating system, and that socket will be turned on when
the computer decides the solar panel temperature is not hot enough to heat
the pool water. This allows a gas heater to turn on and heat the pool.

As I understand it;
When the solar panels are hot enough, the gas booster, which has its
water supply in series with the closed circuit solar heating line,
will be de-activated and the solar heated water simply passes through
the gas booster heating element. Only the solar panel supplies heat.

When the solar panel temperature sensor indicates that it cannot
supply heat to the water, the controller will activate the gas booster
to heat the water instead. The gas heated water will still circulate
via the solar panels and at the same time the controller feeds power
to the circulating pump.

I would like to have the pump turn on if either one (or both) of the
conditions exist, but I need some advice. What I envision is that the pump
power cord will be plugged into some kind of back box containing a couple of
relays. The black box will have two inputs, one from the clock/timer and
the other from the solar computer. It either (or both) of the inputs has
voltage, the output to the pump power cord will have voltage. If neither
has voltage, there would be no voltage to the pump power cord.

What you are looking for is a fully automatic system to avoid having
to move the pump cord from one socket to the other and with no
requirement for user intervention (other than setting the manual timer
period).

Since it would be mandatory for the pump to be operating whenever the
gas booster is operating the solar/gas controller would need to assume
priority control over the system so as to avoid the pump stopping when
it was already operating under manual timer control.

The simplest method involves working directly with 240Vac and unless
you are certified to do so (qualified electrician) you should not
attempt to carry out any modification or design. You need to be fully
aware of the correct procedures and wiring techniques which ensure
complete isolation of users from the 240Vac supply. Nevertheless, here
is one method of achieving your requirements. I will not be able to
specify the components, construction techniques or wiring
specifications since this is fairly time consuming.

First, both the manual timer and solar/gas controller devices should
receive their 240Vac supply from the same distribution circuit breaker
(ELCB).

The control function you require can be done fairly simply using just
2 relays. Both relays would need to be rated for 240Vac motor/pump
operation suitable for a 1HP motor(746W). The relay which supplies
power to the outlet socket from the manual timer would need a single
make contact (usually a SPDT relay) whereas the relay which supplies
power to the outlet socket from the solar/gas booster controller must
have a make contact and a separate break contact (usually a DPDT).

The Active line output from the manual timer must be routed via a
break contact on the relay which is powered from the solar/gas
controller and then to one side of the coil and also to one terminal
of the make contact on the manual timer relay. The other terminal of
the make contact on the manual timer relay is wired directly to the
Active pin of the outlet socket. The other side of the coil on the
manual timer relay goes to Neutral as does the Neutral pin on the
outlet socket.

The Active line from the solar/gas controller is wired directly to one
side of the solar/gas relay coil and also to one terminal of the
second contact on this relay. The make terminal of this contact is
wired directly to the Active pin on the outlet socket. The other side
of the coil is connected to Neutral.

In operation, let us assume the pump is operating under manual timer
control. The manual relay will be operated directly from the timer via
the break (NC contact) of the solar/gas relay which is currently not
operated. The outlet socket will supply power to the pump.

If, while under manual timer control the solar/gas controller
activates, then the solar/gas relay will operate and it will now feed
power to the outlet socket. When the solar/gas relay operates the NC
contact in series with the manual timer relay coil and contact will
open and thus cause the manual timer relay to release. The solar/gas
relay has now assumed priority control over the outlet socket. Should
the wiring not be arranged in this manner it would be possible for the
pump to stop working when the timer period expired while in manual
timer mode and if the solar/gas controller was now activated after the
pump switched off, it would not be able to start again. No water would
circulate and the gas booster might be damaged due to non-circulation
of the heated water.

Again, I would urge you to not undertake any work if you are not a
qualified electrician.

I have the pump (750 watt), the clock/timer, and the solar computer. I need
to build the black box.

I suspect this is not rocket science but choosing and connecting the relays
is beyond me. I'd welcome any advice.

Please let me now if this is unclear and I will elaborate.

Thanks,
Clark
(in Melbourne, Australia)

 

[Ross Herbert]

On Thu, 24 Feb 2005 05:51:02 GMT, Ross Herbert
<rherber1@bigpond.net.au> wrote:

On Thu, 24 Feb 2005 11:50:31 +1100, "cb" <clarkb@nospamplease.com
wrote:

I have a swimming pool pump that I'd like to turn on if either one (or both)
of two conditions exist:

Presently the pump's power cord can be plugged into either a clock/timer so
it will turn on at certain times of the day that I choose,

OR

The pump's 240vac power cord can be plugged into a socket attached to a
'computer' on a solar heating system, and that socket will be turned on when
the computer decides the solar panel temperature is not hot enough to heat
the pool water. This allows a gas heater to turn on and heat the pool.

As I understand it;
When the solar panels are hot enough, the gas booster, which has its
water supply in series with the closed circuit solar heating line,
will be de-activated and the solar heated water simply passes through
the gas booster heating element. Only the solar panel supplies heat.

When the solar panel temperature sensor indicates that it cannot
supply heat to the water, the controller will activate the gas booster
to heat the water instead. The gas heated water will still circulate
via the solar panels and at the same time the controller feeds power
to the circulating pump.


I would like to have the pump turn on if either one (or both) of the
conditions exist, but I need some advice. What I envision is that the pump
power cord will be plugged into some kind of back box containing a couple of
relays. The black box will have two inputs, one from the clock/timer and
the other from the solar computer. It either (or both) of the inputs has
voltage, the output to the pump power cord will have voltage. If neither
has voltage, there would be no voltage to the pump power cord.

What you are looking for is a fully automatic system to avoid having
to move the pump cord from one socket to the other and with no
requirement for user intervention (other than setting the manual timer
period).

Since it would be mandatory for the pump to be operating whenever the
gas booster is operating the solar/gas controller would need to assume
priority control over the system so as to avoid the pump stopping when
it was already operating under manual timer control.

The simplest method involves working directly with 240Vac and unless
you are certified to do so (qualified electrician) you should not
attempt to carry out any modification or design. You need to be fully
aware of the correct procedures and wiring techniques which ensure
complete isolation of users from the 240Vac supply. Nevertheless, here
is one method of achieving your requirements. I will not be able to
specify the components, construction techniques or wiring
specifications since this is fairly time consuming.

First, both the manual timer and solar/gas controller devices should
receive their 240Vac supply from the same distribution circuit breaker
(ELCB).

The control function you require can be done fairly simply using just
2 relays. Both relays would need to be rated for 240Vac motor/pump
operation suitable for a 1HP motor(746W). The relay which supplies
power to the outlet socket from the manual timer would need a single
make contact (usually a SPDT relay) whereas the relay which supplies
power to the outlet socket from the solar/gas booster controller must
have a make contact and a separate break contact (usually a DPDT).

The Active line output from the manual timer must be routed via a
break contact on the relay which is powered from the solar/gas
controller and then to one side of the coil and also to one terminal
of the make contact on the manual timer relay. The other terminal of
the make contact on the manual timer relay is wired directly to the
Active pin of the outlet socket. The other side of the coil on the
manual timer relay goes to Neutral as does the Neutral pin on the
outlet socket.

PS. I just realised a feedback path will exist to keep the manual
timer relay operated if only the Active is routed via the solar/gas
relay contact. To rectify this problem the Neutral line connected to
the manual timer relay coil also needs to be routed via a separate
break contact (N/C) on the solar/gas relay. This means the solar/gas
relay must now have 3 contact sets instead of 2.

Hope I haven't overlooked anything else.

The Active line from the solar/gas controller is wired directly to one
side of the solar/gas relay coil and also to one terminal of the
second contact on this relay. The make terminal of this contact is
wired directly to the Active pin on the outlet socket. The other side
of the coil is connected to Neutral.

In operation, let us assume the pump is operating under manual timer
control. The manual relay will be operated directly from the timer via
the break (NC contact) of the solar/gas relay which is currently not
operated. The outlet socket will supply power to the pump.

If, while under manual timer control the solar/gas controller
activates, then the solar/gas relay will operate and it will now feed
power to the outlet socket. When the solar/gas relay operates the NC
contact in series with the manual timer relay coil and contact will
open and thus cause the manual timer relay to release. The solar/gas
relay has now assumed priority control over the outlet socket. Should
the wiring not be arranged in this manner it would be possible for the
pump to stop working when the timer period expired while in manual
timer mode and if the solar/gas controller was now activated after the
pump switched off, it would not be able to start again. No water would
circulate and the gas booster might be damaged due to non-circulation
of the heated water.

Again, I would urge you to not undertake any work if you are not a
qualified electrician.



I have the pump (750 watt), the clock/timer, and the solar computer. I need
to build the black box.

I suspect this is not rocket science but choosing and connecting the relays
is beyond me. I'd welcome any advice.

Please let me now if this is unclear and I will elaborate.

Thanks,
Clark
(in Melbourne, Australia)