Trinamic QSH6018-86-28-310 - 60 x 60mm Stepper Motor, 1.8 Degree, 3.10Nm, 0 - 84Vdc, 2.8A QSH6018-86-28-310 Fiche De Données

QSH6018 Manual (V1.03 / 06-February-2008) 

 

9 

Copyright © 2008, TRINAMIC Motion Control GmbH & Co. KG 

 

Basically, the motor torque is proportional to the motor current, as long as the current stays at a 
reasonable level. At the same time, the power consumption of the motor (and driver) is proportional 
to the square of the motor current. Optimally, the motor should be chosen to bring the required 
performance at the rated motor current. For a short time, the motor current may be raised above this 
level in order to get increased torque, but care has to be taken in order not to exceed the maximum 
coil temperature of 130°C respectively a continuous motor operation temperature of 90°C. 
 

150% 

≤150% 

225% 

Limit operation to a few seconds 

125% 

125% 

156% 

Operation possible for a limited time

100% 

100% 

100%  

= 2 * I

RMS_RATED

 * R

COIL

 

Normal operation 

85% 

85% 72% 

Normal operation 

75% 

75% 56% 

Normal operation 

50% 

50% 25% 

Reduced microstep exactness due to 
torque reducing in the magnitude of 
detent torque 

38% 

38% 14% 

-“- 

25% 

25% 6% 

-“- 

0% 

see detent 

torque 

0% 

Motor might loose position if the 
application’s friction is too low 

Hints: 

Q: How to choose the optimum current setting?  
 
A1: Generally, you choose the motor in order to give the desired performance at nominal current. 
For short time operation, you might want to increase the motor current to get a higher torque than 
specified for the motor. In a hot environment, you might want to work with a reduced motor 
current in order to reduce motor self heating. 
The Trinamic drivers allow setting the motor current for up to three conditions:  
- 

Stand still (choose a low current) 

- 

Nominal operation (nominal current) 

- 

High acceleration (if increased torque is required: You may choose a current above the nominal 
setting, but be aware, that the mean power dissipation shall not exceed the motors nominal 
rating) 

 
A2: If you reach the velocity limit, it might be a good idea to reduce the motor current, in order to 
avoid resonances occurring. Please see the hints on choosing the driver voltage. 
 
Q: What about energy saving – how to choose standby current?  
 
A1: Most applications do not need much torque during motor stand-still. You should always reduce 
motor current during stand still. This reduces power dissipation and heat generation. Depending on 
your application, you typically at least can half power dissipation. There are several aspects why 
this is possible: In stand still, motor torque is higher than at any other velocity. Thus, you do not 
need the full current even with a static load! Your application might need no torque at all, but you 
might need to keep the exact microstep position: Try how low you can go in your application. If 
the microstep position exactness does not matter for the time of stand still, you might even reduce 
the motor current to zero, provided that there is no static load on the motor and enough friction in 
order to avoid complete position loss.