Motor data
Motor data
(OP)
I want some data on some old WRIM-motors we use in our plant, to check their settings. The manufacturer doesn't exist anymore, so I don't know where to obtain the data. Can I assume any values or is there any average value I can use for:
1. Safe hot stall time?
2. Permissible start attemps / hour?
The nameplate values of the motors is:
Power: 500kW; 450kW; 220kW; 200kW
rpm: 1483rpm; 495rpm; 1479rpm; 1497rpm
Stator V 3300V
Stator I 115A; 110V; 51.9A; 49A
Rotor V 855V; 613V; 399V; 390V
Rotor I 347A; 434A; 323A; 305A
Frequency 50Hz
Any help will be appreciated
Thanks
RCC
1. Safe hot stall time?
2. Permissible start attemps / hour?
The nameplate values of the motors is:
Power: 500kW; 450kW; 220kW; 200kW
rpm: 1483rpm; 495rpm; 1479rpm; 1497rpm
Stator V 3300V
Stator I 115A; 110V; 51.9A; 49A
Rotor V 855V; 613V; 399V; 390V
Rotor I 347A; 434A; 323A; 305A
Frequency 50Hz
Any help will be appreciated
Thanks
RCC





RE: Motor data
Your permissible start attempts per hour will be related to the inrush current reduction achieved with the rotor resistive bank.
For inrush current reduction to 4.37 times Full load current, the winding will have 80 CM/Amp allowing around two starts in succession not longer than 20 seconds each per hour.
Further inrush current reduction will allow geometrical increase of starts. For instance if the inrush current is reduced to 2.18 times full load current, the winding will have 160 CM/Amp allowing 2 x ( 160/80)^2 = 8 starts in succession, and so on.
This is only speculation and you should do some trial test with the lower inrush current achievable, and then measure the winding temperature rise during and after every start, do not exceed 105°C since these are old motors with probably low insulation class.
RE: Motor data
RE: Motor data
jb:
The only nameplate data avaliable is the data in my first post.
There is 4 different size motors (Slipring motors, same manufacturer)
The only data again:
Motor 1
Power: 500kW
rpm: 1483rpm
Stator V: 3300V
Stator I: 115A
Rotor V: 855V
Rotor I: 347A
freq: 50Hz
Motor 2
Power: 450kW
rpm: 495rpm
Stator V: 3300V
Stator I: 110A
Rotor V: 613V
Rotor I: 434A
freq: 50Hz
Motor 3
Power: 220kW
rpm: 1479rpm
Stator V: 3300V
Stator I: 51.9A
Rotor V: 399V
Rotor I: 323A
freq: 50Hz
Motor 4
Power: 200kW
rpm: 1497rpm
Stator V: 3300V
Stator I: 49A
Rotor V: 390V
Rotor I: 305A
Frequency: 50Hz
RE: Motor data
Motor 1
Power: 500kW
rpm: 1483rpm
Stator V: 3300V
Stator I: 115A
Rotor V: 855V
Rotor I: 347A
freq: 50Hz
///PF=500kW/(sqrt3 x 3.3kV x 115A)=0.76
is somewhat low for EFF assumed = 1. What has happened to the motor efficiency value? Is it unavailable or hard to read on the motor nameplate?\\\
Motor 2
Power: 450kW
rpm: 495rpm
Stator V: 3300V
Stator I: 110A
Rotor V: 613V
Rotor I: 434A
freq: 50Hz
///PF=450kW/(sqrt3 x 3.3 x 110A)=0.72 under assumed EFF=1\\\
Motor 3
Power: 220kW
rpm: 1479rpm
Stator V: 3300V
Stator I: 51.9A
Rotor V: 399V
Rotor I: 323A
freq: 50Hz
///PF=220kW/(sqrt3 x 3.3 x 51.9A)=0.74 under assumed EFF=1\\\
Motor 4
Power: 200kW
rpm: 1497rpm
Stator V: 3300V
Stator I: 49A
Rotor V: 390V
Rotor I: 305A
Frequency: 50Hz
///PF=200kW/(sqrt3 x 3.3 x 49A)=0.71 under assumed EFF=1\\\