Siemens G85139 operating instructions Motor Overload Protection, Block Diagram

2. INSTALLATION English

2.3.5 Motor Overload Protection

When operated below rated speed, the cooling effect of fans fitted to the motor shaft is reduced. Consequentially, most motors require de-rating for continuous operation at low frequencies. To ensure that motors are protected against overheating under these conditions, a PTC temperature sensor must be fitted to the motor and connected to the inverter control terminals as shown in Figure 7.

Note: To enable the trip function, set parameter P051, P052 or P053 =19.

8

MOTOR

PTC

7

1kΩ

Inverter Control Terminals

9

Figure 7: Motor Overload PTC Connection

2.3.6 Block Diagram

	≥	4.7 kΩ		+10V
			1
V: 0 - 10 V			2	0V
	OR	AIN+
2 - 10 V
		AIN-	3	AD
			4
–
24 V
+		DIN1
		DIN2	5
		DIN3	6
OR			7
Power Supply for				+15V
PI Feedback			8
Transducer				0V
or other load.			9
	RL1	RL1B	10
		RL1C	11

	PE
	1/3 AC 230 V
	3 AC 380 - 500 V	SI
	PE	L/L1, N/L2
		or
		L/L1, N/L2, L3
Jog	~
	P
	RS485
CPU
		3 ~

PE

U, V, W

		M
Figure 8: Block Diagram
© Siemens plc 1997		G85139-H1750-U049-B
	13	26/09/97