Curtis 1239E - Voltage Limits

Return to TOC Curtis 1239E-1269E Manual, os 37.0 RevA – May 2021
3 — APPLICATION-SPECIFIC FEATURES
pg. 27
VOLTAGE LIMITS
High Power Circuit
For the high power circuit, overvoltage protection cuts back regen braking to prevent damage to
batteries and other electrical system components due to high B+ voltage. Undervoltage protection
prevents systems from operating at voltages below their design thresholds.
e four thresholds below are calculated from the Nominal Voltage, Undervoltage Cutback Range
(dened by Kp UV and Ki UV), User Overvoltage, and User Undervoltage parameter settings, and
the controller’s minimum and maximum voltage ratings.
B+ Overvoltage = Either B+ Maximum Voltage or User Overvoltage × Nominal Voltage,
whichever is lower.
Severe B+ Overvoltage = B+ Overvoltage (see previous item) + 10 V.
B+ Undervoltage = Either B+ Minimum Voltage or User Undervoltage × Nominal
Voltage, whichever is higher.
Severe B+ Undervoltage = B+ Undervoltage point - Undervoltage Cutback Range or
B+ Brownout voltage, whichever is higher.
B+ Brownout Voltage. If the capacitor voltage falls below the B+ brownout voltage, motor current
is switched o. If the voltage rises above the brownout threshold, motor current is switched back on.
No controller reset occurs based on B+ voltage.
Low Power Circuit
For the low power circuit, KSI voltage is monitored to ensure it is within the design limits of the
controller. A KSI undervoltage or overvoltage fault will trip if the KSI voltage falls outside the
allowed range.
KSI Brownout Voltage. If the KSI voltage falls below the KSI brownout voltage, motor current is
switched o. If the KSI voltage stays below the brownout voltage for greater than 64 ms, the controller
will reset (equivalent to cycling the keyswitch). If the KSI voltage rises above the brownout voltage
before 64 ms have passed, motor current is switched back on and driving can continue.
Quick Links:
Controller voltage
ratings p.155
User/parameter voltage
limits p.69