Options; Three-Phase Current Regulation (Cr) Option; Current Imbalance Detection (Cid) Option; Lug Kit (Lk) Option - Siemens POWER CONTROL Series Operation Manual

3PCI SCR Power Controller Series Manual
transformers monitor the true rms current, and feed the information to option CL, which limits the true rms
current regardless of the process control signal.

1.5. Options

Several options are available on the 3PCI. Several of these options are listed below and explained in the
subsections that follow.
•

Three-phase Current Regulation (CR) Option

•

Current Imbalance Detection (CID) Option

•

Lug Kit (LK) Option

•

Extended Ramp (ER) and Fast Ramp (FR) Options.

Most options require current transformers (CTs), which are standard on models rated from 25 A through
225 A. CTs are shipped separately on models rated from 350 A and higher.
1.5.1. Three-phase Current Regulation (CR) Option
The 3-phase Current Regulation (CR) option compares the feedback signal to the control signal, so the line
current will be linear to the control signal, and regulated to maintain a constant current level at the controller
output despite load changes. Current regulation is adjustable from 5% to 125% of the CT rating.
1.5.2. Current Imbalance Detection (CID) Option
The Current Imbalance Detection (CID) option continuously compares the load currents of each phase.
When an imbalance exceeds a pre-determined limit value (5% to 50%), a set of form-C contacts may be
used to alarm and/or turn off the process.
1.5.3. Lug Kit (LK) Option
If required by an application, an optional lug kit (Option LK) is offered. Lug kits are available on 350 A
through 1200 A units. Lugs are provided on 25 A through 225 A units.
1.5.4. Extended Ramp (ER) and Fast Ramp (FR) Options
The increasing rate of the output voltage RMS value is limited to prevent high inrush currents with
transformer-coupled loads or with elements having high cold-to-hot resistance ratios. With a nominal gain
setting, the rate of increase is limited to approximately 100% per second. Additional protective circuits prevent
excessive output bursts due to the fluctuations of re-applied AC source voltage.
The standard ramp time is 1 second. By specifying option ER, the soft-start ramp is increased to 4 seconds.
A fast ramp option (FR) reduces the ramp time to 0.100 seconds (100 ms).

1.6. Technical Specifications

Specifications for the 3PCI SCR Power Controller are given in Table 1-2 and Table 1-1.

Table 1-1. General Technical Specifications

Input line voltage
Line frequency
Current rating
Thermostat contact
rating
Input signal
Version 1.2 (19000325)
Item
1
208, 240, 400, 480, 600 V
1
50/60 Hz (no circuit change is necessary for either)
1
25 A or 1200 A
AC
120 V , 5 A, resistive
AC
Galvanic isolation: 0-1.5 V (min) 0-15 V (max)
s
Description
(+10%, -20%) 3-phase
AC
per model number (see Table 1-2)
AC
Introduction
1-3