(_:111) Cooling time constant = 1500 s The cooling time constant
The Thermal time constant of the motor must be indicated by the manufacturer. The Cooling time
constant is the multiple of the Thermal time constant.
Step 8: Load-Jam Protection
The setting for the parameter Threshold for operate as secondary value is calculated as follows:
[fo_threshold for operate, 1, en_US]
The parameter Operate delay can remain at the default setting of 1 s.
The parameter Threshold for warning is set to 75 % of the operating threshold, that is, 75 % ⋅ 1.6 A =
1.2 A.
The parameter Warning delay can remain at the default setting of 2 s.
The parameter Release delay is set to the motor-starting time.
The following figure illustrates an example of a complete motor-protection characteristic curve. In general, a
characteristic curve consists of different protection functions. Each function is responsible for a special motor
fault type.
[dwexmocu-160812-03.tif, 2, en_US]
Figure 4-1
Example of a Complete Motor-Protection Characteristic Curve
Step 9: Switchgear Control
Make sure that no unauthorized switching of a circuit breaker or a disconnector is performed. You can
authorize the switching with the specific password and the related security prompts.
Setting Example
28 SIPROTEC 5, Additional Information on the Protection of Explosion-Proof Motors with Type of Protection Increased Safety e,
Manual
C53000-H5050-C078-1, Edition 03.2019
To Next Page
Loading...
Need help?
General
