Ametek PF3 SCR Series Operation and maintenance manual

SCR POWER CONTROLLER
Instruction, Operation and
Maintenance Manual
Number: 9100034
Revision 3
530 Lakeview Plaza Blvd, Ste C
Worthington, Ohio, USA 43085
Toll F re e : 1 - 8 88- PWR- C NTL (7 9 7 -26 85)
Ph o n e: 61 4 -3 0 8-550 0
Fa x : 614 - 3 08 - 5506
Web: w w w .hd rpow e r. c o m
PF3 SCR Series
60-1200 Amperes
Three-phase
Phase-fired

This manual applies to all Model PF3 SCR Power Controls. Former PF1/PF3 manual – 9100014 has been
replaced with this manual.
For the support representative nearest you, please call Ametek HDR Power Systems main office at (614)-308-
5500.
Revision 1 September 2014 Initial Release
Revision 2 July 2015 Revised Address
Revision 3 Aug 2022 General Revision
 2022 by Ametek HDR Power Systems. No portion of this document may be reproduced either mechanically or electronically without the
prior consent of Ametek HDR Power Systems.

PF3 SCR Power Controller Table of Contents
Rev 3 Ametek HDR Power Systems i
TABLE OF CONTENTS
IMPORTANT SAFETY INSTRUCTIONS ............................................................................................................. 1
CHAPTER 1 - DESCRIPTION .............................................................................................................................. 3
1.1 General Description 3
1.2 Application 3
1.3 Operation 3
1.4 Specification 3
CHAPTER 2 - OPTIONS ...................................................................................................................................... 5
2.1 General 5
2.2 Option OC (Three-Phase Overcurrent Trip) 5
2.3 Option CL/OC (Current Limit/Overcurrent Trip) 5
2.4 Option CR/OC (Current Regulation/Overcurrent Trip) 5
2.5 Option PR (Power Regulation with Current Limit) 6
2.6 Option ER (Extended Ramp) 6
2.7 Option LG (Lug Kit) 6
2.8 Additional Options 6
CHAPTER 3 - INSTALLATION ............................................................................................................................ 7
3.1 Mounting the PF3 7
3.2 Input/Output Wiring 7
3.3 Fan Wiring (applicable to models rated 90 A and higher) 7
3.4 Wiring Overtemperature Contacts 8
3.5 Command Signal Input 8
3.6 Determining Line Frequency 9
3.7 Voltage Changeover 9
3.8 Options 10
CHAPTER 4 - OPERATION ............................................................................................................................... 13
4.1 General 13
4.2 Front Panel Indicators 13
4.3 Command Input Control 13
4.4 Remote Manual Control with a Potentiometer 14
4.5 Auto/Manual Control with a Controller and Remote Potentiometer 15
4.6 On/Off Control 16
4.7 Shutdown 17
4.8 Unbalance Alarm 17
4.9 Shorted SCR Alarm 19
CHAPTER 5 – OPTIONS SETUP ...................................................................................................................... 21
5.1 Option OC (Overcurrent Trip) 21
5.2 Option CL/OC (Current Limit/Over Current Trip) 21
5.3 Option CR/OC (Current Regulation/Over Current Trip) 22
5.4 Option PR 22
CHAPTER 6 - THEORY...................................................................................................................................... 23
6.1 Functional Description 23
6.2 Overview of the PF3 23
6.3 Digital Firing Control Circuit 23
6.4 Pulse-Train Firing 23
6.5 Phase-Lock Loop 23
6.6 SPAN and ZERO Controls 24
6.7 Voltage-Squared Feedback 24

Table of Contents PF3 SCR Power Controller
ii Ametek HDR Power Systems Rev 3
6.8 Shut-down 24
6.9 Soft-Start Circuit 24
CHAPTER 7 – TROUBLESHOOTING ............................................................................................................... 25
7.1 Customer-Service Program 25
7.2 Troubleshooting Typical Symptoms 25
7.3 Static Precautions when Servicing 25
7.4 Environmental Problems 26
7.5 Input Power and Load Connections 26
7.6 Correcting Troubles in the PF3 Itself 27
CHAPTER 8 - SERVICE ..................................................................................................................................... 29
8.1 Communication Procedures 29
8.2 Spare Parts Orders – Routine or Emergency 29
8.3 Spare Parts List 30
8.4 Drawing List 31
CHAPTER 9 – WARRANTY POLICY ................................................................................................................ 33
9.1 Warranty 33
9.2 In-house Repair Services 33
APPENDIX .......................................................................................................................................................... 35
Appendix A – System Schematic 35
Appendix B – 60-225 A Outline 36
Appendix C – 350-500 A Outline 37
Appendix D – 650 A Outline 38
Appendix E – 800-1200 A Outline 39
Appendix F – Declaration of Conformity 40

PF3 SCR Power Controller Table of Contents
Rev 3 Ametek HDR Power Systems iii
TABLE OF CONTENTS
Par. Title Page
ILLUSTRATIONS
Figure 3.1 Fan and Thermostat Connections .................................................................................................. 8
Figure 3.2 Isolated/Non-Isolated Switches ...................................................................................................... 9
Figure 3.3 T1, T2 Transformer Connections ................................................................................................... 9
Figure 3.4 Current Transformer Connections ............................................................................................... 10
Figure 3.5 Typical PF3 Line and Load Connections ..................................................................................... 11
Figure 4.1 Control Panel .................................................................................................................................. 13
Figure 4.2 Process Controller Input Connections ........................................................................................ 14
Figure 4.3 Remote Control with a Potentiometer ......................................................................................... 15
Figure 4.4 Auto/Man Control with Controller and Remote Potentiometer ................................................. 16
Figure 4.5 On/Off Control ................................................................................................................................ 16
Figure 4.6 Shutdown Control .......................................................................................................................... 17
Figure 4.7 Unbalance Alarm Board ................................................................................................................ 18
Figure 4.8 Shorted SCR Alarm Board ............................................................................................................ 19
Figure 4.9 Unbalance Block Diagram ............................................................................................................. 20
Figure 5.1 Current Limit/Trip Board ............................................................................................................... 21
Figure 6.1 AC Switch and SCR On-time ......................................................................................................... 23
TABLES
Table 1.1 PF3 Model Number Breakdown........................................................................................................ 3
Table 1.2 General Specifications of PF3 Models ............................................................................................ 4
Table 3.1 Wire Size Information ........................................................................................................................ 7
Table 3.2 Transformer Voltage Wiring ........................................................................................................... 10
Table 7.1 Troubleshooting Chart (Symptoms and Solutions) ..................................................................... 27
Table 7.2 Torque Specifications ..................................................................................................................... 27
Table 8.1 PF3 Spare Parts List ........................................................................................................................ 30
Table 8.2 PF3 Drawing List ............................................................................................................................. 31

Table of Contents PF3 SCR Power Controller
iv Ametek HDR Power Systems Rev 3

PF3 SCR Power Controller Safety Instructions
Rev 3 Ametek HDR Power Systems 1
SAVE THESE INSTRUCTIONS
IMPORTANT SAFETY INSTRUCTIONS
WARNING
Observe all warnings and cautions in this manual. Failure to do so may result in serious injury or death.
Refer all service to properly trained and qualified service personnel. Never work alone.
Lethal voltages exist on exposed heat sinks even if the power controller is turned off. Remove power and lock
out power before attempting any service.
This manual contains important safety instructions that must be followed during the installation and
maintenance of the SCR Power controller. Read this manual thoroughly before attempting to operate this
Power controller.
An appropriate branch circuit fused disconnect or circuit breaker with this Power Controller is required to
ensure the safety of operating personnel.
CAUTION
HAZARDOUS VOLTAGES exist at the Power Controller Heat Sinks and at the Load, AT ALL TIMES, when
input voltage is connected. This condition exists even when the Power Controller is set to deliver zero output.
Printed circuit boards contain sensitive components that can be damaged by electrostatic discharge (ESD).
Observe precautions for handling electrostatic sensitive devices. Reference Maintenance and Troubleshooting
(Chapter 7) of this manual for details
In case of fire, use a dry chemical fire extinguisher to put out the fire. Using a liquid fire extinguisher may
cause electric shock.
The SCR Power Controller makes use of components dangerous for the environment (electronic printed circuit
boards, electronic components). The components removed must be taken to specialized collection and
disposal centers.
E151547
100kA SCCR
IEC 947-5-1

Safety Instructions PF3 SCR Power Controller
2 Ametek HDR Power Systems Rev 3

PF3 SCR Power Controller Description
Rev 3 Ametek HDR Power Systems 3
CHAPTER 1 - Description
1.1 General Description
The PF3 is a Three-phase, phase-fired power controller, and can operate with a wide variety of input
signals and line voltages up to 575 Vac and currents ranging from 60 through 1200 amperes. The
PF3’s output voltage is proportional to its input signal. The PF3 features pulse-train firing which
provides high immunity to possible SCR firing disturbances, and phase-lock loop circuitry which
ensures line frequency synchronization. Other features are input isolation from ground, soft-start, and
automatic restart circuitry. Terminals are provided to permit connection of a variety of external control
methods. A more detailed description of the features mentioned above is provided in Chapter 6 of this
manual.
1.2 Application
Phase-Fired SCR Power Controllers provide infinitely variable firing angles for precise control of three-
phase power to resistive or inductive loads. This precise control is essential for transformer coupled
loads or loads with great resistance changes due to temperature or start-up. Phase-Fired units may
also be used on straight resistive loads as well, but the lower power factor and higher harmonics may
present a problem to other equipment mounted nearby. A zero fired model would be a better choice.
1.3 Operation
The PF3 accomplishes power control by the switching action of a pair of inverse-parallel power SCRs.
The switching, or gating, of the SCRs is controlled by a digital firing control circuit synchronized “in
phase” with line frequency (either 50 or 60 Hz). A soft-start (approximately a 12 cycle ramp) feature is
standard that allows the Power Controller to fire into the primary of a transformer or to control power to
heating elements which have a large resistance change during start-up. The output may be adjusted
by the on-board multi-turn potentiometers or by a voltage or current signal from a process controller.
ZERO and SPAN controls allow the user to calibrate the SCR unit's output to the process command
signal. Terminals are available for connection of a remote manual potentiometer.
1.4 Specification
Specifications for the PF3 SCR power controller are given in Tables 1.1 and 1.2.
Table 1.1 PF3 Model Number Breakdown
PF3 – 480 – 225 – CR – UB – 01
NOTE: N.O. Thermostat is included in current ratings above 60 A.
120 Vac - 120
240 Vac - 240
400 Vac - 400
480 Vac - 480
575 Vac -
575
60 A rms - 60
90 A rms - 90
120 A rms - 120
180 A rms - 180
225 A rms - 225
350 A rms - 350
500 A rms - 500
650 A rms - 650
800 A rms - 800
1000 A rms - 1000
1200 A rms
-
1200
N.O. Thermostat - NO
N.C. Thermostat - NC
RMS Current Limit/OC - CL
RMS Current Reg/OC - CR
Over Current Trip - OC
True Power Reg/CL – PR
Unbalance Alarm – UB
Shorted SCR Alarm - SF
Extended Ramp - ER
Lug Kit (>225 A) - LG
Can have multiple selections
4-20 mA - 01
0-10 Vdc - 02
0-5 Vdc - 03
Auto/Man - 04
Manual Pot input - 05
Others
-
xx

Description PF3 SCR Power Controller
4 Ametek HDR Power Systems Rev 3
Table 1.2 General Specifications of PF3 Models
Input line voltage: * 120, 240, 400, 480, or 575 Vac,
+10%, -15% , Three-phase
Line frequency: * 50 or 60 Hz
Current rating:
*
As indicated by model number (refer to Table 1.1)
Thermostat contact rating: 120 Vac, 5 A; resistive
Input Signal:
Non-isolated
Isolated
0 to 1.5 V (min); 0 to 10 V (max)
0 to 6 mA (min); 0 to 20 mA (max)
Control methods: 1. Potentiometer, 5 kΩ, 1/2 watt (Customer-supplied).
2. Dry contact closure (customer-supplied).
3. Temperature or process controller
*
*
Control signal input impedance:
Non-isolated input
Isolated input
1500 Ω
500 Ω
Control signal isolation:
From SCRs 2,500 Vac
From ac power input lines 2,500 Vac
From chassis 500 Vac
Power output:
Voltage regulation Voltage Squared
Power output linearity versus
control signals input
+2% (Non-isolated)
+5% (Isolated)
Power SCRs protection:
Current surge Subcycle I² T semiconductor fuse.
Transient voltage spikes (dv/dt)
SCCR Rating
Metal Oxide Varistor (MOV) and R-C snubber across each SCR pair; all
SCRs have PIV rating of 1,400 V.
100kA
Miscellaneous:
Phase-firing timebase 0 º to 180 º conduction per SCR
Controls: ZERO and SPAN potentiometers; 10-turn, screwdriver-adjustable.
Approvals UL/cUL (E151547), CE
Fan
-
cooling power (as applicable):
For 90 A through 225 A units 0.42 amperes, 50 VA (50 Hz)
0.38 amperes, 46 VA (60 Hz)
For 350 A through 500 A units 0.63 amperes, 76 VA (50 Hz)
0.57 amperes, 69 VA (60 Hz)
For 650 A through 1200 A units 4.2 amperes, 504 VA (50 Hz)
3.6 amperes, 432 VA (60 Hz)
Ambient Temperature range:
Environment 32 ºF to 122 ºF ( 0 ºC to 50 ºC) surrounding air
Pollution degree 2, Overvoltage Category III
Storage 14 ºF to 158 ºF ( -10 ºC to 70 ºC)
Weight per unit: Current Rating
60 through 225 A
350, 500 A
650 A
800, 1000, 1200 A
lbs
47
60
126
231
kg
18.2
27.3
57.3
105
Outline and mounting: See appropriate drawing in Appendix
* Specify with order
** If you will be using temperature/process controller, specify its output; e.g., 4-20 mA, 0-10 Vdc, 2-10 Vdc,
etc. with your order.
NOTE: The PF3 should be tested or operated with an adequate load since an open output will have line
voltage at the load connections.