Operating Instructions

Chapter 4 - Parameters and Menu Structure
Parameters (M3)
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Siemens Industry, Inc.
Siemens BT300 HVAC Drive
DPD01809
Smart Infrastructure
2019-05-29
Motor thermal load (P3.9.10)
Setting the value to 130% means that the nominal temperature will be reached with 130% of the motor’s
nominal current.
Figure 19: Motor Temperature Calculation.
Stall Protection (P3.9.11 through P3.9.14)
The motor stall protection protects the motor from short-time overload situations such as one caused by a
stalled shaft. The reaction time of the stall protection can be set shorter than that of the motor thermal
protection. The stall state is defined with two parameters: Stall Current (P3.9.12) and Stall Frequency Limit
(P3.9.14). If the current is higher than the set limit and the output frequency is lower than the set limit, the stall
state is true. There is actually no real indication of the shaft rotation. Stall protection is a type of over-current
protection.
Stall current (P3.9.12)
The current can be set to 0.0…2*IL. For a stall stage to occur, the current must have exceeded this limit. See
the following figure. If Motor current limit (P3.1.1.7) is changed, this parameter is automatically calculated to
90% of the current limit.
NOTE:
To guarantee desired operation, this limit must be set below the current limit.