# Multi speed 220v AC motor circuit

#### alaaj99

Joined Apr 7, 2016
5
Hello
My fruit blender smoked a couple days ago, I opened it and found a single phase motor and a board (totally burned).
The motor is OK. I found a Diac\Triac circuit some where and modified it for 4 speed control.

D1 = BTB16-800cw = 16 amps triac.
C1+C2 rated at 400v.
R1 rated at 1W. "To be honest I just copy it from the original circuit I found but I don't know what is the role of it cause I'm just a hobbyist"
The motor is a single phase 220v 400W.
What do you think about it? Any thing wrong? Any suggestions?
I want to add a fuse but I don't know where and what value should it be

Joined Jul 18, 2013
22,855
A 5a fuse in the AC L1 line, if this is a supply that has L1 & L2 (in place of neutral) then you should have a fuse in both L1/L2.
I assume it is a Universal motor? i.e. brushed.
Max.

#### alaaj99

Joined Apr 7, 2016
5
A 5a fuse in the AC L1 line, if this is a supply that has L1 & L2 (in place of neutral) then you should have a fuse in both L1/L2.
I assume it is a Universal motor? i.e. brushed.
Max.
A 5 amps fuse?! isn't it too much for a 400 watt motor?!
If V = 220, P = 400. Then i = 1.81, R= 121.
And yes you're right it's a brushed motor.

Joined Jul 18, 2013
22,855
The initial inrush is very high on most motors, particularly series motors, especially if starting at full rpm.
Fuse it at 2a you could be in for nuisance blowing.!
R is irrelevant.
Max.

#### alaaj99

Joined Apr 7, 2016
5
The initial inrush is very high on most motors, particularly series motors, especially if starting at full rpm.
Fuse it at 2a you could be in for nuisance blowing.!
R is irrelevant.
Max.
Valuable information, thank you, I'm still learning.
I hope that you have reviewed the circuit and did not find errors in it because I have not implemented it yet.

Joined Jul 18, 2013
22,855
Look like you have four preset SW's/speeds in place of the traditional Pot.
Max.

#### alaaj99

Joined Apr 7, 2016
5
Look like you have four preset SW's/speeds in place of the traditional Pot.
Max.
Yes it's a ''fruit blender''. It has 6 switches on the front panel, 2 momentary switches, one for slowest/off, one for full speed/pulse. The rest switches are normal.
something like this one

#### Bordodynov

Joined May 20, 2015
2,841
A 5 amps fuse?! isn't it too much for a 400 watt motor?!
If V = 220, P = 400. Then i = 1.81, R= 121.
And yes you're right it's a brushed motor.
Fuses are divided into 3 groups by the speed of operation. You can take a fuse at 3A if it is a slow type. It can work for several tens of seconds.