Curtis 1253 - Undervoltage Parameters; Low Voltage Cutback; Low Voltage Cutback Rate; Contactor Control Parameters

Curtis 1253 Manual, Rev. F
27
Blue Ox Rev. A, draft #1 [3 August 2007]
LOVOLT CUTBACK
e Low Voltage Cutback parameter sets the undervoltage threshold. At this
threshold voltage, the output current starts to taper o. Output current is
reduced until reaching zero, at the rate established by the low voltage cutback
rate parameter (see below). Low voltage cutback can be set from 32–42 V
for 48V models and from 54–70 V for 80V models.
LOVOLT CB RATE
e Low Voltage Cutback Rate parameter determines how sharply the current
limit decreases when the battery voltage falls below the undervoltage threshold
(see above). e low voltage cutback rate can be set from 0 to 20, with cutback
response being more gradual at lower values and more abrupt at higher values.
A setting of 0 disables the cutback function entirely; this is not recommended,
as the cutback function protects the system from operating at voltages lower
than its electronics were designed for.
CONTACT CNTRL
e Main Contactor Control parameter is programmed to correspond to the
way the contactor is wired. If the contactor is part of the 1253 circuit, this
parameter should be programmed On. If the contactor is controlled externally,
this parameter should be programmed O.
CONT PULL IN
e Main Contactor Pull-in Voltage parameter allows a high initial voltage
when the contactor driver rst turns on, to ensure contactor closure. After the
controller detects that the contactor is closed, this peak voltage will be applied
for 0.1 second to ensure a reliable close; the voltage will then drop to the pro-
grammed contactor holding voltage (see below).
For 48V models, the pull-in voltage can be set from 18–60 V. For 80V
models, the range is 30–100 V.
CONT HOLDING
e Contactor Holding Voltage parameter allows a reduced average voltage to
be applied to the contactor coil once it has closed. e holding voltage must
be set high enough to hold the contactor closed under all shock and vibration
conditions it will be subjected to.
For 48V models, the contactor holding voltage range is 12–60 V, with
48 V being the typical default setting. For 80V models, the range is 20–100 V,
with 80 V being the typical default setting.
3 — PROGRAMMABLE PARAMETERS: Undervoltage and Contactor Control Parameters
Undervoltage Parameters
Contactor Control Parameters