bonitron M3539-S600Ax3-1500VDC, Справочное руководство

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User’s Manual
11
4. O
PERATION
4.1.
F
UNCTIONAL
D
ESCRIPTION
The M3539-S600Ax3-1500VDC Overvoltage Protector (4118355) is
connected to the DC bus. When the voltage goes above a certain
threshold, the SCRs will fire, limiting the voltage from going higher. The
energy is dissipated through the field resistance. This is designed with
heatsinks to handle time constants up to 12 seconds without fan or
other air circulation. Once the current drops below the SCR latching
threshold, the circuit turns off resets for another high voltage spike.
Unit has three parallel SCRs, each capable of carrying 600A peak. This
will allow for parallel load resistor connections.
WARNING!
Each connection must have a separate resistor element! If the
resistor connections are all connected at the crowbar module, the
SCRs will not share current, and may misfire!
This can cause overheating and catastrophic failure!
4.1.1. J
UMPER
S
ELECTION
4.1.1.1.
TB2-O
VERVOLTAGE
S
ETPOINT
S
ELECTION
J
UMPERS
A jumper is used to determine the overvoltage setpoint. This is the
point at which the SCRs will fire regardless of other conditions. The
voltage is sensed between TB1 and the DC- power connection.
Jumper adjustment:
For 1200V: connect TB2-1 to TB2-4
For 1300V: connect TB2-1 to TB2-3
For 1400V: connect TB2-1 to TB2-2
For 1500V: no jumper
4.1.1.2.
TB7 - R
ESPONSE
T
IME
S
ELECTION
J
UMPER
This jumper determines the response time of the circuit. If the jumper is
installed, the unit will fire when the voltage sensed on TB1 is above the
setpoint within 2ms.
If the jumper is not installed, the unit will fire within 20ms.
4.1.1.3.
TB8 - C
ROWBAR
F
IRE
S
IGNAL
O
PERATION
J
UMPER
This jumper determines the firing operation of the external override
signal. See Section 4.1.2.2 for details on the settings.
4.1.2. I/O I
NPUTS AND
O
UTPUTS
4.1.2.1.
TB1-1&2 H
IGH
V
OLTAGE
S
IGNAL
+
The unit will sense the DC BUS positive voltage from TB1-1 or TB1-2.
The differential voltage between this terminal and the DC- terminals will
determine when the SCR crowbar fires.
These terminals are an electrical node, and are connected on the
board. Do not hook the DC- reference to these terminals as it will be a
direct short.