I have an old furnace with a one-speed-at-a-time-based on the wiring
fan motor.

I once rewired it, using the schematic, to see if I could find a lower
speed, so I know the schematic is correct, but in my dotage, I can't
understand it!

It calls it a "direct drive fan motor" and it has 4 wires coming out
of it. It appears that either 2 or 3 wires are to be connected at a
given time, although that doesn't correspond to my vague memory.
The wires a

White Common, connected at all times
Black High, perhaps connected at all times, if you go by the
schematic
Blue Medium
Red Low

The schematic shows 2 wires connected to the motor and a iiuc a 3rd
optional wire.

On Monday, December 7, 2015 at 2:33:07 AM UTC-6, Micky wrote:
I have an old furnace with a one-speed-at-a-time-based on the wiring
fan motor.

I once rewired it, using the schematic, to see if I could find a lower
speed, so I know the schematic is correct, but in my dotage, I can't
understand it!

....do you have *any* search abilities?

On Monday, December 7, 2015 at 3:33:07 AM UTC-5, Micky wrote:
I have an old furnace with a one-speed-at-a-time-based on the wiring
fan motor.

I once rewired it, using the schematic, to see if I could find a lower
speed, so I know the schematic is correct, but in my dotage, I can't
understand it!

It calls it a "direct drive fan motor" and it has 4 wires coming out
of it. It appears that either 2 or 3 wires are to be connected at a
given time, although that doesn't correspond to my vague memory.
The wires a

White Common, connected at all times
Black High, perhaps connected at all times, if you go by the
schematic
Blue Medium
Red Low

The schematic shows 2 wires connected to the motor and a iiuc a 3rd
optional wire.

What's unclear? It has three possible speeds. If there are only
two wires going to it, pick you speed. If there are three wires
going to it, then one of those is for heat and one for cooling.
Typically cooling is on high, heat would be on medium.

On 12/7/2015 3:32 AM, Micky wrote:
I have an old furnace with a one-speed-at-a-time-based on the wiring
fan motor.

I once rewired it, using the schematic, to see if I could find a lower
speed, so I know the schematic is correct, but in my dotage, I can't
understand it!

It calls it a "direct drive fan motor" and it has 4 wires coming out
of it. It appears that either 2 or 3 wires are to be connected at a
given time, although that doesn't correspond to my vague memory.
The wires a

White Common, connected at all times
Black High, perhaps connected at all times, if you go by the
schematic
Blue Medium
Red Low

The schematic shows 2 wires connected to the motor and a iiuc a 3rd
optional wire.


It's been a year or so since I wired one of those.
The one I did, the circuit board had terminals
labelled HEAT, COOL, and PARK, if memory serves.
The one I did, had red on heat, blue on cool,
and black was on park. The family wasn't getting
enough AC in the second floor. I changed the
AC blower from medium to high.

In your case, sounds like you may wish to take
blue off HEAT, and put it on PARK. Take red off
park, and put it on heat.

Remit $74.50 for internet consult, please.


--
..
Christopher A. Young
learn more about Jesus
.. www.lds.org
..
..

On Mon, 07 Dec 2015 03:32:35 -0500, Micky
wrote:

I have an old furnace with a one-speed-at-a-time-based on the wiring
fan motor.

I once rewired it, using the schematic, to see if I could find a lower
speed, so I know the schematic is correct, but in my dotage, I can't
understand it!

It calls it a "direct drive fan motor" and it has 4 wires coming out
of it. It appears that either 2 or 3 wires are to be connected at a
given time, although that doesn't correspond to my vague memory.
The wires a

White Common, connected at all times
Black High, perhaps connected at all times, if you go by the
schematic
Blue Medium
Red Low

The schematic shows 2 wires connected to the motor and a iiuc a 3rd
optional wire.

You only use white and one of the others for each speed

On Monday, December 7, 2015 at 3:33:07 AM UTC-5, Micky wrote:
I have an old furnace with a one-speed-at-a-time-based on the wiring
fan motor.

I once rewired it, using the schematic, to see if I could find a lower
speed, so I know the schematic is correct, but in my dotage, I can't
understand it!

It calls it a "direct drive fan motor" and it has 4 wires coming out
of it. It appears that either 2 or 3 wires are to be connected at a
given time, although that doesn't correspond to my vague memory.
The wires a

White Common, connected at all times
Black High, perhaps connected at all times, if you go by the
schematic
Blue Medium
Red Low

The schematic shows 2 wires connected to the motor and a iiuc a 3rd
optional wire.

Sometimes those are used in an air handler that has both ac and heat. The fan speed may be high for ac but one of the lower speeds for heat.

jamesgang wrote:
On Monday, December 7, 2015 at 3:33:07 AM UTC-5, Micky wrote:
I have an old furnace with a one-speed-at-a-time-based on the wiring
fan motor.

I once rewired it, using the schematic, to see if I could find a lower
speed, so I know the schematic is correct, but in my dotage, I can't
understand it!

It calls it a "direct drive fan motor" and it has 4 wires coming out
of it. It appears that either 2 or 3 wires are to be connected at a
given time, although that doesn't correspond to my vague memory.
The wires a

White Common, connected at all times
Black High, perhaps connected at all times, if you go by the
schematic
Blue Medium
Red Low

The schematic shows 2 wires connected to the motor and a iiuc a 3rd
optional wire.

Sometimes those are used in an air handler that has both ac and heat. The fan speed may be high for ac but one of the lower speeds for heat.

Right cold air is heavy so needs high speed to push.

On Mon, 7 Dec 2015 04:31:14 -0800 (PST), trader_4
wrote:

On Monday, December 7, 2015 at 3:33:07 AM UTC-5, Micky wrote:
I have an old furnace with a one-speed-at-a-time-based on the wiring
fan motor.

I once rewired it, using the schematic, to see if I could find a lower
speed, so I know the schematic is correct, but in my dotage, I can't
understand it!

It calls it a "direct drive fan motor" and it has 4 wires coming out
of it. It appears that either 2 or 3 wires are to be connected at a
given time, although that doesn't correspond to my vague memory.
The wires a

White Common, connected at all times
Black High, perhaps connected at all times, if you go by the
schematic
Blue Medium
Red Low

The schematic shows 2 wires connected to the motor and a iiuc a 3rd
optional wire.

What's unclear? It has three possible speeds. If there are only
two wires going to it, pick you speed. If there are three wires
going to it, then one of those is for heat and one for cooling.

If that were the case, that would be certainly make it unclear to
someone who didn't expect that, who had never seen a fan motor hard
wired for two different speeds.

But, no. There is no separate heating and cooling speed.

The schematic is unclear, perhaps incorrect in this one small part,
but I did't post this when I wrote it because I figured out the rest
of the fan relays and enough of my memory came back that I lost
interest in the details of the fan.

Typically cooling is on high, heat would be on medium.

On Mon, 07 Dec 2015 08:41:12 -0500, wrote:

On Mon, 07 Dec 2015 03:32:35 -0500, Micky
wrote:

I have an old furnace with a one-speed-at-a-time-based on the wiring
fan motor.

I once rewired it, using the schematic, to see if I could find a lower
speed, so I know the schematic is correct, but in my dotage, I can't
understand it!

It calls it a "direct drive fan motor" and it has 4 wires coming out
of it. It appears that either 2 or 3 wires are to be connected at a
given time, although that doesn't correspond to my vague memory.
The wires a

White Common, connected at all times
Black High, perhaps connected at all times, if you go by the
schematic
Blue Medium
Red Low

The schematic shows 2 wires connected to the motor and a iiuc a 3rd
optional wire.

You only use white and one of the others for each speed

I'm sure that's right. Long ago I tried the other speeds, on the
faint hope that one would be slower than what I had, but I had the
slowest, as the color indicated. (So I started closing the bedroom
door when the AC was on. Strangely, I've never wanted to close the
door when the heat is on, even though it's the same fan speed. Old
furnace.) The schematic seems to show that 3 wires from the furnace
are connected to the fan, but I don't think that's so.

On Monday, December 7, 2015 at 11:01:35 PM UTC-5, Micky wrote:
On Mon, 7 Dec 2015 04:31:14 -0800 (PST), trader_4
wrote:

On Monday, December 7, 2015 at 3:33:07 AM UTC-5, Micky wrote:
I have an old furnace with a one-speed-at-a-time-based on the wiring
fan motor.

I once rewired it, using the schematic, to see if I could find a lower
speed, so I know the schematic is correct, but in my dotage, I can't
understand it!

It calls it a "direct drive fan motor" and it has 4 wires coming out
of it. It appears that either 2 or 3 wires are to be connected at a
given time, although that doesn't correspond to my vague memory.
The wires a

White Common, connected at all times
Black High, perhaps connected at all times, if you go by the
schematic
Blue Medium
Red Low

The schematic shows 2 wires connected to the motor and a iiuc a 3rd
optional wire.

What's unclear? It has three possible speeds. If there are only
two wires going to it, pick you speed. If there are three wires
going to it, then one of those is for heat and one for cooling.

If that were the case, that would be certainly make it unclear to
someone who didn't expect that, who had never seen a fan motor hard
wired for two different speeds.


It is the case and it is clear to everyone reading this, except you.



But, no. There is no separate heating and cooling speed.


So then it's as simple as can be. Put the one wire on the
speed of your choice.


The schematic is unclear, perhaps incorrect in this one small part,
but I did't post this when I wrote it because I figured out the rest
of the fan relays and enough of my memory came back that I lost
interest in the details of the fan.

Typically cooling is on high, heat would be on medium.

On Monday, December 7, 2015 at 3:30:39 PM UTC-5, Tony Hwang wrote:
jamesgang wrote:
On Monday, December 7, 2015 at 3:33:07 AM UTC-5, Micky wrote:
I have an old furnace with a one-speed-at-a-time-based on the wiring
fan motor.

I once rewired it, using the schematic, to see if I could find a lower
speed, so I know the schematic is correct, but in my dotage, I can't
understand it!

It calls it a "direct drive fan motor" and it has 4 wires coming out
of it. It appears that either 2 or 3 wires are to be connected at a
given time, although that doesn't correspond to my vague memory.
The wires a

White Common, connected at all times
Black High, perhaps connected at all times, if you go by the
schematic
Blue Medium
Red Low

The schematic shows 2 wires connected to the motor and a iiuc a 3rd
optional wire.

Sometimes those are used in an air handler that has both ac and heat. The fan speed may be high for ac but one of the lower speeds for heat.

Right cold air is heavy so needs high speed to push.

And I'd be surprised that low speed is optimal either. Never seen an
AC that uses low fan speed for cooling.

On Tue, 8 Dec 2015 06:13:05 -0800 (PST), trader_4
wrote:

On Monday, December 7, 2015 at 11:01:35 PM UTC-5, Micky wrote:
On Mon, 7 Dec 2015 04:31:14 -0800 (PST), trader_4
wrote:

On Monday, December 7, 2015 at 3:33:07 AM UTC-5, Micky wrote:
I have an old furnace with a one-speed-at-a-time-based on the wiring
fan motor.

I once rewired it, using the schematic, to see if I could find a lower
speed, so I know the schematic is correct, but in my dotage, I can't
understand it!

It calls it a "direct drive fan motor" and it has 4 wires coming out
of it. It appears that either 2 or 3 wires are to be connected at a
given time, although that doesn't correspond to my vague memory.
The wires a

White Common, connected at all times
Black High, perhaps connected at all times, if you go by the
schematic
Blue Medium
Red Low

The schematic shows 2 wires connected to the motor and a iiuc a 3rd
optional wire.

What's unclear? It has three possible speeds. If there are only
two wires going to it, pick you speed. If there are three wires
going to it, then one of those is for heat and one for cooling.

If that were the case, that would be certainly make it unclear to
someone who didn't expect that, who had never seen a fan motor hard
wired for two different speeds.


It is the case and it is clear to everyone reading this, except you.

It's good that you know about everyone else, when you haven't even
seen the schematic yourself.

But, no. There is no separate heating and cooling speed.

So then it's as simple as can be. Put the one wire on the
speed of your choice.

That leaves 3 wires from the furnace connected to the motor.

The schematic is unclear, perhaps incorrect in this one small part,
but I did't post this when I wrote it because I figured out the rest
of the fan relays and enough of my memory came back that I lost
interest in the details of the fan.

Typically cooling is on high, heat would be on medium.

On Tuesday, December 8, 2015 at 3:24:47 PM UTC-5, Micky wrote:
On Tue, 8 Dec 2015 06:13:05 -0800 (PST), trader_4
wrote:

On Monday, December 7, 2015 at 11:01:35 PM UTC-5, Micky wrote:
On Mon, 7 Dec 2015 04:31:14 -0800 (PST), trader_4
wrote:

On Monday, December 7, 2015 at 3:33:07 AM UTC-5, Micky wrote:
I have an old furnace with a one-speed-at-a-time-based on the wiring
fan motor.

I once rewired it, using the schematic, to see if I could find a lower
speed, so I know the schematic is correct, but in my dotage, I can't
understand it!

It calls it a "direct drive fan motor" and it has 4 wires coming out
of it. It appears that either 2 or 3 wires are to be connected at a
given time, although that doesn't correspond to my vague memory.
The wires a

White Common, connected at all times
Black High, perhaps connected at all times, if you go by the
schematic
Blue Medium
Red Low

The schematic shows 2 wires connected to the motor and a iiuc a 3rd
optional wire.

What's unclear? It has three possible speeds. If there are only
two wires going to it, pick you speed. If there are three wires
going to it, then one of those is for heat and one for cooling.

If that were the case, that would be certainly make it unclear to
someone who didn't expect that, who had never seen a fan motor hard
wired for two different speeds.


It is the case and it is clear to everyone reading this, except you.

It's good that you know about everyone else, when you haven't even
seen the schematic yourself.

But, no. There is no separate heating and cooling speed.

So then it's as simple as can be. Put the one wire on the
speed of your choice.

That leaves 3 wires from the furnace connected to the motor.


You posted this:


"I have an old furnace with a one-speed-at-a-time-based on the wiring
fan motor. "

"The schematic shows 2 wires connected to the motor and a iiuc a 3rd
optional wire. "


That would imply that it has only two wires and runs at only one speed.
IDK what "one speed at a time" means, otherwise. Fans with 3 speeds can
only run at one speed at a time.


"But, no. There is no separate heating and cooling speed. "

Are you as sure about that as you are the number of wires? It would
seem odd to run wires for two speeds to the fan motor and not use
them.

On Wed, 9 Dec 2015 05:47:57 -0800 (PST), trader_4
wrote:

On Tuesday, December 8, 2015 at 3:24:47 PM UTC-5, Micky wrote:
On Tue, 8 Dec 2015 06:13:05 -0800 (PST), trader_4
wrote:

On Monday, December 7, 2015 at 11:01:35 PM UTC-5, Micky wrote:
On Mon, 7 Dec 2015 04:31:14 -0800 (PST), trader_4
wrote:

On Monday, December 7, 2015 at 3:33:07 AM UTC-5, Micky wrote:
I have an old furnace with a one-speed-at-a-time-based on the wiring
fan motor.

I once rewired it, using the schematic, to see if I could find a lower
speed, so I know the schematic is correct, but in my dotage, I can't
understand it!

It calls it a "direct drive fan motor" and it has 4 wires coming out
of it. It appears that either 2 or 3 wires are to be connected at a
given time, although that doesn't correspond to my vague memory.
The wires a

White Common, connected at all times
Black High, perhaps connected at all times, if you go by the
schematic
Blue Medium
Red Low

The schematic shows 2 wires connected to the motor and a iiuc a 3rd
optional wire.

What's unclear? It has three possible speeds. If there are only
two wires going to it, pick you speed. If there are three wires
going to it, then one of those is for heat and one for cooling.

If that were the case, that would be certainly make it unclear to
someone who didn't expect that, who had never seen a fan motor hard
wired for two different speeds.


It is the case and it is clear to everyone reading this, except you.

It's good that you know about everyone else, when you haven't even
seen the schematic yourself.

But, no. There is no separate heating and cooling speed.

So then it's as simple as can be. Put the one wire on the
speed of your choice.

That leaves 3 wires from the furnace connected to the motor.


You posted this:


"I have an old furnace with a one-speed-at-a-time-based on the wiring
fan motor. "

"The schematic shows 2 wires connected to the motor and a iiuc a 3rd
optional wire. "


That would imply that it has only two wires

You only quoted part of what I wrote.

And no, it implies that the schematic shows it has 3 wires, but that I
don't understand how it can work with three wires.

Why don't you just skip this thread and go on to something else.

and runs at only one speed.
IDK what "one speed at a time" means, otherwise. Fans with 3 speeds can
only run at one speed at a time.


"But, no. There is no separate heating and cooling speed. "

Are you as sure about that as you are the number of wires? It would
seem odd to run wires for two speeds to the fan motor and not use
them.

On Wednesday, December 9, 2015 at 2:10:29 PM UTC-5, Micky wrote:

You posted this:


"I have an old furnace with a one-speed-at-a-time-based on the wiring
fan motor. "

"The schematic shows 2 wires connected to the motor and a iiuc a 3rd
optional wire. "


That would imply that it has only two wires

You only quoted part of what I wrote.

And no, it implies that the schematic shows it has 3 wires, but that I
don't understand how it can work with three wires.


I quoted what defined the number of wires and connection.
What the schematic shows is one thing. How it's actually wired
is another. It wouldn't be the first time a schematic was for various
models and the particular model you have doesn't use all the possible
wires. So, what is actually there?



Why don't you just skip this thread and go on to something else.


Why don't you learn how to make one complete post with all the
information? Many people here have tried to explain it to you
based on the info that you provided, but apparently it's not
sinking in. With three wires you get two speeds.

"And no, it implies that the schematic shows it has 3 wires, but that I
don't understand how it can work with three wires. "

One for high speed for cooling, one for low or med speed for heat,
one neutral. 1+1+1 = 3 Got it now?

On Wed, 09 Dec 2015 14:10:10 -0500, Micky
wrote:

On Wed, 9 Dec 2015 05:47:57 -0800 (PST), trader_4
wrote:

On Tuesday, December 8, 2015 at 3:24:47 PM UTC-5, Micky wrote:
On Tue, 8 Dec 2015 06:13:05 -0800 (PST), trader_4
wrote:

On Monday, December 7, 2015 at 11:01:35 PM UTC-5, Micky wrote:
On Mon, 7 Dec 2015 04:31:14 -0800 (PST), trader_4
wrote:

On Monday, December 7, 2015 at 3:33:07 AM UTC-5, Micky wrote:
I have an old furnace with a one-speed-at-a-time-based on the wiring
fan motor.

I once rewired it, using the schematic, to see if I could find a lower
speed, so I know the schematic is correct, but in my dotage, I can't
understand it!

It calls it a "direct drive fan motor" and it has 4 wires coming out
of it. It appears that either 2 or 3 wires are to be connected at a
given time, although that doesn't correspond to my vague memory.
The wires a

White Common, connected at all times
Black High, perhaps connected at all times, if you go by the
schematic
Blue Medium
Red Low

The schematic shows 2 wires connected to the motor and a iiuc a 3rd
optional wire.

What's unclear? It has three possible speeds. If there are only
two wires going to it, pick you speed. If there are three wires
going to it, then one of those is for heat and one for cooling.

If that were the case, that would be certainly make it unclear to
someone who didn't expect that, who had never seen a fan motor hard
wired for two different speeds.


It is the case and it is clear to everyone reading this, except you.

It's good that you know about everyone else, when you haven't even
seen the schematic yourself.

But, no. There is no separate heating and cooling speed.

So then it's as simple as can be. Put the one wire on the
speed of your choice.

That leaves 3 wires from the furnace connected to the motor.


You posted this:


"I have an old furnace with a one-speed-at-a-time-based on the wiring
fan motor. "

"The schematic shows 2 wires connected to the motor and a iiuc a 3rd
optional wire. "


That would imply that it has only two wires

You only quoted part of what I wrote.

And no, it implies that the schematic shows it has 3 wires, but that I
don't understand how it can work with three wires.

Why don't you just skip this thread and go on to something else.

and runs at only one speed.
IDK what "one speed at a time" means, otherwise. Fans with 3 speeds can
only run at one speed at a time.


"But, no. There is no separate heating and cooling speed. "

Are you as sure about that as you are the number of wires? It would
seem odd to run wires for two speeds to the fan motor and not use
them.
My old furnace has a 3 wire motor. Onewas common, one was "constant
run" (1/6 HP, 600RPM more or less, and the other was full fan - for
heating/cooling. On most furnaces they would be set up that when the
furnace calls for the blower to come on it switched from low to high.

On mine, the low was run full time, and the high came on with the low
for normal heating/cooling. It worked that way for years, even though
it was not the proper way.

A lot of newer furnaces have multi-speed direct drive motors. The HVAC
guy selects the speed that produces the specified heat rise for
heating, and the specified temp drop for AC. That will virtually
always be 2 different speeds, and will deprnd on the static pressure
in the ducts (in other words how much restriction in the system)

The motor in yours is likely designed for use in a furnace / central
air handler combination that allows for separate heating and cooling
speeds, or a constant run fan. If there are 4 wires it could support
both.

My new one has a 3 phase brushless DC motor with variable speed drive
controller.

On Wed, 09 Dec 2015 22:51:07 -0500, wrote:

On Wed, 09 Dec 2015 14:10:10 -0500, Micky
wrote:

On Wed, 9 Dec 2015 05:47:57 -0800 (PST), trader_4
wrote:

On Tuesday, December 8, 2015 at 3:24:47 PM UTC-5, Micky wrote:
On Tue, 8 Dec 2015 06:13:05 -0800 (PST), trader_4
wrote:

On Monday, December 7, 2015 at 11:01:35 PM UTC-5, Micky wrote:
On Mon, 7 Dec 2015 04:31:14 -0800 (PST), trader_4
wrote:

On Monday, December 7, 2015 at 3:33:07 AM UTC-5, Micky wrote:
I have an old furnace with a one-speed-at-a-time-based on the wiring
fan motor.

I once rewired it, using the schematic, to see if I could find a lower
speed, so I know the schematic is correct, but in my dotage, I can't
understand it!

It calls it a "direct drive fan motor" and it has 4 wires coming out
of it. It appears that either 2 or 3 wires are to be connected at a
given time, although that doesn't correspond to my vague memory.
The wires a

White Common, connected at all times
Black High, perhaps connected at all times, if you go by the
schematic
Blue Medium
Red Low

The schematic shows 2 wires connected to the motor and a iiuc a 3rd
optional wire.

What's unclear? It has three possible speeds. If there are only
two wires going to it, pick you speed. If there are three wires
going to it, then one of those is for heat and one for cooling.

If that were the case, that would be certainly make it unclear to
someone who didn't expect that, who had never seen a fan motor hard
wired for two different speeds.


It is the case and it is clear to everyone reading this, except you.

It's good that you know about everyone else, when you haven't even
seen the schematic yourself.

But, no. There is no separate heating and cooling speed.

So then it's as simple as can be. Put the one wire on the
speed of your choice.

That leaves 3 wires from the furnace connected to the motor.


You posted this:


"I have an old furnace with a one-speed-at-a-time-based on the wiring
fan motor. "

"The schematic shows 2 wires connected to the motor and a iiuc a 3rd
optional wire. "


That would imply that it has only two wires

You only quoted part of what I wrote.

And no, it implies that the schematic shows it has 3 wires, but that I
don't understand how it can work with three wires.

Why don't you just skip this thread and go on to something else.

and runs at only one speed.
IDK what "one speed at a time" means, otherwise. Fans with 3 speeds can
only run at one speed at a time.


"But, no. There is no separate heating and cooling speed. "

Are you as sure about that as you are the number of wires? It would
seem odd to run wires for two speeds to the fan motor and not use
them.
My old furnace has a 3 wire motor. Onewas common, one was "constant
run" (1/6 HP, 600RPM more or less, and the other was full fan - for
heating/cooling. On most furnaces they would be set up that when the
furnace calls for the blower to come on it switched from low to high.

On mine, the low was run full time, and the high came on with the low
for normal heating/cooling. It worked that way for years, even though
it was not the proper way.

A lot of newer furnaces have multi-speed direct drive motors. The HVAC
guy selects the speed that produces the specified heat rise for
heating, and the specified temp drop for AC. That will virtually
always be 2 different speeds, and will deprnd on the static pressure
in the ducts (in other words how much restriction in the system)

The motor in yours is likely designed for use in a furnace / central
air handler combination that allows for separate heating and cooling
speeds, or a constant run fan. If there are 4 wires it could support
both.

That would explain it. It's just not used to its full capacity in
this furnace. Thanks.

My new one has a 3 phase brushless DC motor with variable speed drive
controller.