Wesley BC-620-4CA - Manual (Page 107)

Curtis 1234/36/38 Manual,
OS
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2 3 J U LY 2 0 0 8 D R A F T
7 — VCL
VCL FUNCTIONS SPECIFIC TO 1234/36/38 AC CONTROLLERS
Function descriptions are provided here for the functions that are unique to
these controllers. They are presented in the same format that is used in the
VCL Common Functions Manual for the common functions.
ENABLE_PRECHARGE()
This function is designed to precharge the capacitor bank before engaging a main
contactor thereby preventing current surges and to protect controller internal com-
ponents and main contactor tips. This function turns on the request for precharge
of the capacitor bank from KSI. When the precharge function is enabled, power will
be supplied to the capacitor bank until the voltage is within 3 volts of KSI, or one
second has expired, or the precharge resistor energy range has been exceeded. The
current state of precharge is shown by the precharge variable (Precharge_State),
which has the following values:
0 – Precharge has not yet been done.
1 – Precharge is in progress.
2 – Precharge has passed.
3 – Precharge has been aborted by the Disable_Precharge() function.
4 – Precharge has exceeded the precharge resistor energy limit.
5 – Precharge has exceeded the one-second time limit.
Syntax Enable_Precharge()
Parameters None.
Returns
0 – Precharge not enabled.
1 – Precharge successfully enabled.
Error Codes None.
Example Enable_Precharge()
This will attempt to precharge the capacitor bank.