Precision Control Systems 3629C - Manual (Page 6)

MODEL 3629C 2 04/10/2007
FEATURES (Continued)
14. Connection for a remote reset switch, which, if momentarily closed, resets the Over Current Trip relay and resets the
circuit to allow the load voltage to ramp from zero to the desired value.
The switch can also be used to provide remote "on-off" control. Closure of the switch immediately interrupts the SCR
operation and removes load voltage. (See Figure 20 .)
15. Eight status indicators provide the following information:
A. "COMMAND INDICATOR" LED, the intensity of which, is proportional to the command signal.
B."LINE C" LED, the intensity of which, is proportional to the magnitude of the line 3 load current.
C."LINE B" LED, the intensity of which, is proportional to the magnitude of the line 2 load current.
D."LINE A" LED, the intensity of which, is proportional to the magnitude of the line 1 load current.
E."LINE-OK" LED when on, indicates that all three phases are applied.
F. "SHORTED SCR" LED, when on, indicates that an SCR has failed in the shorted mode or is repeatedly miss firing.
G. "OVER CURRENT" LED, when on, indicates that the over current trip point has been reached and the SCRs are
de-energized.
H. "CURRENT LIMIT" LED, when on, indicates that the load current has reached the current limit setting and cannot
be increased by raising the command signal.
16. Controller Ready Signal, is available on the command connector. (See Figure 14 ). When this signal remains high, it
indicates one or more of the following events have occurred:
A. Over current.
B. One or more of the line phases is not present.
C. One or more phases are not present on the firing circuit board. (Circuit fuse may be cleared.)
D. The phase lock is not enabled.
E. The gate drive is not enabled.
F. The Over Current Trip reset switch may be closed.
17. Choice of Command Signal, (See Figure 12 & Figure 13 )
A. 0 to +5 Volts DC.
B. Potentiometer. 1 Kohm to 20 Kohms.
C. Placing a jumper across the pins on JP1, allows the controller to accept a command signal of 0 to +10 Volts DC.
D. By replacing one resistor, the controller may be configured to accept a 4 to 20mA current loop command signal.
(See Figure 30 .)
18. Operating Modes
The model 3629C was designed to offer four user selectable operating modes. A switch on the circuit board allows
the operator to select the desired mode. (See Figure 30 ). Unless ordered otherwise, the controller is shipped with the
switch in the in-line mode.
IN-LINE
This is an ideal configuration for inductive loads, unbalanced resistive loads and transformer coupled loads. (See
Figure 23 , Figure 27 & Figure 28 .)
INSIDE DELTA
Three phase inside delta control is basically three single phase controllers on the same frame that are operating from
the same command signal. 3629C controllers incorporate SCR's with higher PIV ratings to accommodate the voltages
encountered in an inside delta configuration (See Figure 24 .)
SIX SCR DC
As the name implies, this mode is made to drive a three-phase diode bridge to provide power for many applications
requiring a variable DC source. The gate drive is limited to 120 degrees for this mode. (This is full on for a DC
controller.) (See Figure 25 .)
4-WIRE WYE
When powering a WYE load, it is desirable to use the 4-wire configuration to reduce voltage surges due to open
loads. These open load surges could destroy an SCR. (See Figure 26 .)