EB-60X Installation & Service Manual |
Motor Data Package
3.6
EB-60x Typical Current and Voltage (Wave forms at Motor)
3.6.1
Current Phase C
CSW2
10 mV
V = 40.8 mV
2 ms
VZR 0.0
T = 20.46 ms
DSW2
10 mV
2 ms
TPOS 4
EB-606-C– BDS4-255J is illustrated at 20 amps/div., 2500 rpm, 22.2 lb-ft
3.6.2
Voltage line A-C
1 V
2 ms
DSW1
TPOS 4
1 V
CSW2
V = -2.68 V
VZR 0.04
T = 20.46 ms
EB-606-C– BDS4-255J is illustrated at 100 volts/div., 2500 rpm, 22.2 lb-ft
3.7
EB-60x Intermittent Duty Operation
If a motor operates intermittently, it is not necessary that the peak load torque fall within the
motor’s continuous torque capabilities. However, it is important that the RMS (root mean
square) load torque be inside the continuous duty zone. The key here is that a sufficient OFF
time follows each On time of the motor. Equation 1 (EQ-1) gives the RMS torque:
(EQ-1)
TRMS=
T
T
T
1 1 +
t
2
2 t
2
2+... i t
2
i
t + t + t
1 2 ... i
T
i
= Torque at Time i
t
i
= Duration of time i
This equation assumes t
i
is small compared to the thermal time constant for peak power of
motor (TCTP) for torque values significantly larger than the continuous torque (Tc). This is
not always a good assumption. For cases where torque values significantly exceed Tc, the
following equation is used:
Summary of Contents for EB-9207
Page 52: ......
