Ametek ZF1 SCR Series Operation and maintenance manual

SCR POWER CONTROLLER
Instruction, Operation and
Maintenance Manual
Number: 9100037
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
ZF1 SCR Series
60-1200 Amperes
Single-phase
Zero-fired

This manual applies to all Model ZF1 SCR Power Controls. Former ZF1 manual – 9100029 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.

ZF1 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 Option LG (Lug Kit) 5
2.2 Additional Options 5
CHAPTER 3 - INSTALLATION ............................................................................................................................ 7
3.1 Mounting the ZF1 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 Voltage Changeover 9
CHAPTER 4 - OPERATION ............................................................................................................................... 11
4.1 General 11
4.2 Front Panel Indicators 11
4.3 Command Input Control 11
4.4 Remote Manual Control with a Potentiometer 12
4.5 Auto/Manual Control with a Controller and Remote Potentiometer 13
4.6 On/Off Control 14
4.7 Shutdown 14
CHAPTER 5 - THEORY...................................................................................................................................... 15
5.1 Functional Description 15
5.2 Digital Firing Control Circuit 15
5.3 Variable-Time Base 15
5.4 Pulse-Train Firing 16
5.5 Phase-Lock Loop 16
5.6 SPAN and ZERO Controls 16
5.7 Voltage-Squared Feedback 16
5.8 Shut-down 16
CHAPTER 6 – TROUBLESHOOTING ............................................................................................................... 17
6.1 Customer-Service Program 17
6.2 Troubleshooting Typical Symptoms 17
6.3 Static Precautions when Servicing 17
6.4 Environmental Problems 18
6.5 Input Power and Load Connections 18
6.6 Correcting Troubles in the ZF1 Itself 19
CHAPTER 7 - SERVICE ..................................................................................................................................... 21
7.1 Communication Procedures 21
7.2 Spare Parts Orders – Routine or Emergency 21
7.3 Spare Parts List 22
7.4 Drawing List 23

Table of Contents ZF1 SCR Power Controller
ii Ametek HDR Power Systems Rev 3
CHAPTER 8 – WARRANTY POLICY ................................................................................................................ 25
8.1 Warranty 25
8.2 In-house Repair Services 25
APPENDIX .......................................................................................................................................................... 27
Appendix A – ZF1 System Schematic 27
Appendix B – ZF1 60-225 A Outline 28
Appendix C – ZF1 350-500 A Outline 29
Appendix D – ZF1 650 A Outline 30
Appendix E – ZF1 800-1200 A Outline 31
Appendix F – Declaration of Conformity 32

ZF1 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 Transformer Connections .......................................................................................................... 9
Figure 3.4 Typical ZF1 Line and Load Connections ..................................................................................... 10
Figure 4.1 Control Panel .................................................................................................................................. 11
Figure 4.2 Process Controller Input Connections ........................................................................................ 12
Figure 4.3 Remote Control with a Potentiometer ......................................................................................... 13
Figure 4.4 Auto/Man Control with Controller and Remote Potentiometer ................................................. 13
Figure 4.5 On/Off Control ................................................................................................................................ 14
Figure 4.6 Shutdown Control .......................................................................................................................... 14
Figure 5.1 AC Switch ....................................................................................................................................... 15
TABLES
Table 1.1 ZF1 Model Number Breakdown ........................................................................................................ 3
Table 1.2 General Specifications of ZF1 Models ............................................................................................ 4
Table 3.1 Wire Size Information ........................................................................................................................ 7
Table 3.2 Transformer Voltage Wiring ........................................................................................................... 10
Table 5.1 Variable-Time-Base Relationship (Example) ................................................................................ 15
Table 6.1 Troubleshooting Chart (Symptoms and Solutions) ..................................................................... 19
Table 6.2 Torque Specifications ..................................................................................................................... 19
Table 7.1 ZF1 Spare Parts List ........................................................................................................................ 22
Table 7.2 ZF3 Drawing List .............................................................................................................................. 23

Table of Contents ZF1 SCR Power Controller
iv Ametek HDR Power Systems Rev 3

ZF1 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 6) 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 ZF1 SCR Power Controller
2 Ametek HDR Power Systems Rev 3

ZF1 SCR Power Controller Description
Rev 3 Ametek HDR Power Systems 3
CHAPTER 1 - Description
1.1 General Description
The ZF1 is Single-phase SCR Power Controller. Each of these 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 ZF1’s output voltage is proportional to its input signal. HDR’s zero-fired SCR Power Controls
utilize a variable-time-base that helps maintain constant power to the load. This variable-time-base
also helps minimize temperature overshoot, temperature fluctuations and helps extend the load
element’s life due to reduced thermal shock. The ZF1 also 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.
1.2 Application
Zero-Fired SCR Power Controls provide control of single-phase power by the switching action of two
SCRs connected back to back. By switching at the zero crossing point, RFI (Radio Frequency
Interference) is virtually eliminated. Zero-Fired controllers are versatile enough to be used in place of
mechanical contactors and mercury relays on dryers, kilns, ovens, environmental chambers,
extruders, and most other applications where resistive heating elements are used. Normal Zero-Fired
SCR Power Controllers should never be used on inductive loads.
1.3 Operation
The ZF1 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). 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 ZF1 SCR power controller are given in Tables 1.1 and 1.2.
Table 1.1 ZF1 Model Number Breakdown
ZF1 – 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
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 ZF1 SCR Power Controller
4 Ametek HDR Power Systems Rev 3
Table 1.2 General Specifications of ZF1 Models
Input line voltage: * 120, 240, 400, 480, or 575 Vac,
+10%, -15% , Single-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 isolati
on:
From SCRs 2,500 Vac
From ac power input lines 2,500 Vac
From chassis 500 Vac
Power output:
Power output linearity versus
control signals input
+3%
Power SCRs protection:
Current surge Subcycle I² T semiconductor fuse.
Transient voltage spikes (dv/dt) Metal Oxide Varistor (MOV) and R-C snubber across each SCR pair; all
SCRs have PIV rating of 1,400 V.
SCCR Rating 100kA
Miscellaneous:
Zero-firing timebase Variable see 5.3
Controls: ZERO and SPAN potentiometers; 10-turn, screwdriver-adjustable.
Approvals UL/cUL (E151547), CE
Fan
-
cooling power (as applicable):
For 90 A through 500 A units 0.21 amperes, 25 VA (50 Hz)
0.19 amperes, 23 VA (60 Hz)
For 650 A through 1200 A units 1.2 amperes, 144 VA (50 Hz)
1.4 amperes, 168 VA (60 Hz)
Ambient T
emperature 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 º F ( -10 ºC to 70 ºC)
Weight per unit
Current Rating
l
bs
kg
60 through 225 A
350, 500 A
650 A
800, 1000, 1200 A
22
24
27
71
10
10.9
12.3
32.2
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 ZF1 should be tested or operated with an adequate load since an open output will have line
voltage at the load connections.