Delta Electronics VFD-VL manual All Brake Resistors & Brake Units Used in AC Motor Drives

Appendix B Accessories

B.1 All Brake Resistors & Brake Units Used in AC Motor Drives

230V Series Voltage

460V Series

Applicable		Full Load	Resistor value spec		Brake Torque	Min. Equivalent
Motor
		Torque	for each AC Motor		10%ED	Resistor Value for each
hp	kW	Nm	Drive			AC Motor Drive
7.5	5.5	3.111	2400W 16Ω	125		16Ω
10	7.5	4.148	3000W 12Ω		125	12Ω
15	11	6.186	4800W 9Ω	125		9Ω
20	15	8.248	4800W 6.8Ω		125	6.8Ω
25	18.5	10.281	6000W 6Ω	125		6Ω
30	22	12.338	9600W 5Ω		125	5Ω
40	30	16.497	6000W 5Ω	125		5Ω
50	37	20.6	9600W 4Ω		125	4Ω
7.5	5.5	3.111	500W 50Ω	125		50Ω
10	7.5	4.148	1000W 40Ω		125	40Ω
15	11	6.186	1000W 33Ω	125		33Ω
20	15	8.248	1500W 25Ω		125	25Ω
25	18.5	10.281	4800W 21Ω	125		21Ω
30	22	12.338	4800W 19Ω		125	19Ω
40	30	16.497	6000W 20Ω	125		20Ω
50	37	20.6	9600W 16Ω		125	16Ω
60	45	24.745	9600W 13.6Ω	125		13.6Ω
75	55	31.11	12000W 10Ω		125	10Ω
100	75	42.7	19200W 6.8Ω	125		6.8Ω

NOTE

1.Please select the recommended resistance value (Watt) and the duty-cycle value (ED%).

2.Definition for Brake Usage ED%

Explanation: The definition of the brake usage ED(%) is for assurance of enough time for the brake unit and brake resistor to dissipate away heat generated by braking. When the brake resistor heats up, the resistance would increase with temperature, and brake torque would

decrease accordingly. Recommended cycle time is one minute.

	10 0%
	T1	ED% = T1 /T0 x10 0(%)
	Brake Time
		T0
	Cycle Time
3.	For safety consideration, install an overload relay between the brake unit and the brake resistor.
	In conjunction with the magnetic contactor (MC) prior to the drive, it can perform complete
	protection against abnormality. The purpose of installing the thermal overload relay is to protect

B-2 Revision Nov. 2008, VLE1, SW V1.03