installing a remote switch

[jim]

I have cooling unit with an on/off switch inside the casing. I want to install
a remotely controlled on/off switch. I have already purchased the remote switch and
have tested it on a household light and it works fine at a distance of 25 yards. In fact,
it is an RF type switch that works through walls, etc. The switch (relay) module has
mains input/output wires 240 V A/C and a maximum load of 1000watts.

Here's the wiring diagram of the cooling unit:

http://homepage.ntlworld.com/davidsallows2004/March-13,-2005.gif

I would like to switch the compressor on and off with the remote switch or if that's not
possible, then switch the whole thing on/off.

The question is where do I put it?

 

[Fred Bloggs]

I have cooling unit with an on/off switch inside the casing. I want to install
a remotely controlled on/off switch. I have already purchased the remote switch and
have tested it on a household light and it works fine at a distance of 25 yards. In fact,
it is an RF type switch that works through walls, etc. The switch (relay) module has
mains input/output wires 240 V A/C and a maximum load of 1000watts.

Here's the wiring diagram of the cooling unit:

http://homepage.ntlworld.com/davidsallows2004/March-13,-2005.gif

I would like to switch the compressor on and off with the remote switch or if that's not
possible, then switch the whole thing on/off.

The question is where do I put it?

That particular unit operates by using the refrigerant pressure in the
suction line as a thermostat- closing on pressure rise corresponding to
to cut-in temperature. That particular switch is connected at the bottom
just to the left of the compressor with PK/BR wires labeled "in-line
connectors"- closing those switch contacts, shorts PK/BR and connects
"LINE" to RD on the upper terminal block- RD routes to middle "modular
terminal block" and wire color BR to common RUN/START winding connection
of compressor- then from RUN to BLK and START to WH to CAP to BLK which
is connected to Neutral at upper terminal block. The same pressure
switch also throws power to the FAN and its components. That circuit
also passes the full unit load power and is most likely beyond the
rating of a 1000W remote switch- you may need to use the switch to
control a contactor which closes the main circuit. Also- it is not clear
what you want to do with this control. If you want to enable the unit to
start its normal cooling operation, off otherwise, then put your switch
*in series* with the BR wire at the pressure switch; if you want to
override the temperature regulation, then use your switch to short
switch PK/BR together. At least this is what it looks like to me.

 

[Fred Bloggs]

That particular unit operates by using the refrigerant pressure in the
suction line as a thermostat- closing on pressure rise corresponding to
to cut-in temperature. That particular switch is connected at the bottom
just to the left of the compressor with PK/BR wires labeled "in-line
connectors"- closing those switch contacts, shorts PK/BR and connects
"LINE" to RD on the upper terminal block- RD routes to middle "modular
terminal block" and wire color BR to common RUN/START winding connection
of compressor- then from RUN to BLK and START to WH to CAP to BLK which
is connected to Neutral at upper terminal block. The same pressure
switch also throws power to the FAN and its components. That circuit
also passes the full unit load power and is most likely beyond the
rating of a 1000W remote switch- you may need to use the switch to
control a contactor which closes the main circuit. Also- it is not clear
what you want to do with this control. If you want to enable the unit to
start its normal cooling operation, off otherwise, then put your switch
*in series* with the BR wire at the pressure switch; if you want to
override the temperature regulation, then use your switch to short
switch PK/BR together. At least this is what it looks like to me.

This statement "The switch (relay) module has mains input/output wires
240 V A/C and a maximum load of 1000watts" says nearly nothing specific.
If your switch module throws live power, or if there is any doubt about
what it does exactly, then wire a contactor into the pressure switch
circuit, and use your module to throw power on the contactor coil.