Siemens 420 manual Thermal monitoring functions and overload responses, Heatsink temperature

3 Functions Issue 07/04

3.20.2Thermal monitoring functions and overload responses

Parameter range:	P0290 – P0294
	r0036 – r0037
Warnings	A0504, A0505
Faults	F0004, F0005, F0012, F0020, F0022
Function chart number:	-

Similar to motor protection, the main function of the thermal power module monitoring is to detect critical states. Parameterizable responses are provided to the user which allows the drive system to be still operated at the power limit thus avoiding immediate shutdown. However, the possibilities of assigning parameters only involves interventions below the shutdown threshold which cannot be changed by users.

MICROMASTER 420 has the following thermal monitoring functions:

Heatsink temperature

The monitoring of the heatsink temperature r0037[0] of the power semiconductor (IGBT).

i2t monitoring

The i2t monitoring is used to protect components which have a long thermal time constant in comparison to the semiconductors. An overload with reference to i2t is present if the drive inverter utilization r0036 indicates a value greater than 100 % (utilization as a % referred to rated operation).

Normalized output current

r0027

r0207

100 %

Reaction via P0290

Default: "current reduction"

t

i2t [%]

r0036

P0294 (95 %)

t

A0505

1

0 t

Fig. 3-59 Drive inverter response to an overload condition

Parameter P0290 defines how the drive inverter responds to an overload condition. The following settings are possible:

0"Reduce the output frequency"

1"Shutdown (F0004)"

2"Reduce the pulse frequency and output frequency"

3"Reduce the pulse frequency then shutdown (F0004)"

MICROMASTER 420	Operating Instructions
140	6SE6400-5AA00-0BP0