YASKAWA SGDH User Manual page 399

(3) Precautions on Selecting External Regenerative Resistors
A built-in regenerative resistor is provided for 500 W to 5.0 kW SGDH SERVOPACKs as standard.
When installing an external regenerative resistor with the SERVOPACK, make sure that the resistance is the
same as that of the SERVOPACK's built-in resistor.
If combining multiple small-capacity regenerative resistors to increase the regenerative resistor capacity (W),
select resistors so that the resistance value including error is at least as high as the minimum allowable resistance
shown in the following table.
Connecting a regenerative resistor with the resistance smaller than the minimum allowable resistance may
increase the current flow in the regeneration circuit, resulting in damage to the circuit.
(4) Parameter Setting
Pn600 Regenerative Resistor Capacity
Setting Range
0 to SERVOPACK
capacity
Be sure to set this parameter when installing an external regenerative resistor with the SERVOPACK.
With the factory setting of "0," the SERVOPACK's built-in resistor is used.
Set the regenerative resistor capacity within tolerance value. When the set value is improper, alarm A.32 is not detected cor-
rectly. Also, do not set other than 0 without connecting the regenerative resistor because alarm A.30 or A.33 may be detected.
The set value differs depending on the cooling method of external regenerative resistor:
• For natural air cooling method: Set the value maximum 20 % of the actually installed regenerative resistor capacity (W).
• For forced air cooling method: Set the value maximum 50 % of the actually installed regenerative resistor capacity (W).
For example, set 20 W (100 W × 20 %) for the 100 W external regenerative resistor with natural cooling method: Pn600 = 2
(units: 10 W)
1. When resistors for power are used at the rated load ratio, the resistor temperature increases to between
IMPORTANT
200 °C (392 °F) and 300 °C (572 °F). The resistors must be used at or below the rated values. Check with
the manufacturer for the resistor's load characteristics. Use the regenerative resistors at no more than
20% of the rated load ratio with natural convection cooling, and no more than 50% of the rated load ratio
with forced air cooling.
2. For safety's sake, use the resistors with thermoswitches.
Unit Factory Setting
10 W 0
6-35
6.5 Connecting Regenerative Resistors
Speed
Position Torque
Setting Validation
Immediately
6