ZF2/ZF3 SCR Power Controller
Description
Rev 3
Ametek HDR Power Systems
3
CHAPTER 1 - Description
1.1
General Description
The ZF2 is three-phase 2-leg/4 zero-fired SCR control and the ZF3 is a three-phase, 3-leg/6 zero-fired
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 ZF2/ZF3’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 ZF2/ZF3 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 three-phase power by the switching action of two
SCRs connected back to back in each controlled phase. 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 ZF2/ZF3 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 ZF2/ZF3 SCR power controller are given in Tables 1.1 and 1.2.
Table 1.1 ZF2 and ZF3 Model Number Breakdown
ZF2 (or ZF3) – 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
Unbalance Alarm -
UB
Shorted SCR Alarm -
SF
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
Содержание ZF2 SCR Series
Страница 6: ...Table of Contents ZF2 ZF3 SCR Power Controller iv Ametek HDR Power Systems Rev 3...
Страница 8: ...Safety Instructions ZF2 ZF3 SCR Power Controller 2 Ametek HDR Power Systems Rev 3...
Страница 23: ...ZF2 ZF3 SCR Power Controller Operation Rev 3 Ametek HDR Power Systems 17 Figure 4 9 Unbalance Block Diagram...
Страница 24: ...Operation ZF2 ZF3 SCR Power Controller 18 Ametek HDR Power Systems Rev 3...
Страница 32: ...Troubleshooting ZF2 ZF3 SCR Power Controller 26 Ametek HDR Power Systems Rev 3...
Страница 42: ...Appendix ZF2 ZF3 SCR Power Controller 36 Ametek HDR Power Systems Rev 3 Appendix C ZF2 60 225 A Outline R...
Страница 43: ...ZF2 ZF3 SCR Power Controller Appendix Rev 3 Ametek HDR Power Systems 37 Appendix D ZF2 350 500 A Outline R...
Страница 44: ...Appendix ZF2 ZF3 SCR Power Controller 38 Ametek HDR Power Systems Rev 3 Appendix E ZF2 650 A Outline R...
Страница 45: ...ZF2 ZF3 SCR Power Controller Appendix Rev 3 Ametek HDR Power Systems 39 Appendix F ZF2 800 1200 A Outline R...
Страница 46: ...Appendix ZF2 ZF3 SCR Power Controller 40 Ametek HDR Power Systems Rev 3 Appendix G ZF3 60 225 A Outline R...
Страница 47: ...ZF2 ZF3 SCR Power Controller Appendix Rev 3 Ametek HDR Power Systems 41 Appendix H ZF3 350 500 A Outline R...
Страница 48: ...Appendix ZF2 ZF3 SCR Power Controller 42 Ametek HDR Power Systems Rev 3 Appendix I ZF3 650 A Outline...
Страница 49: ...ZF2 ZF3 SCR Power Controller Appendix Rev 3 Ametek HDR Power Systems 43 Appendix J ZF3 800 1200 A Outline R...
Страница 51: ...Notes...
Страница 52: ...503 Lakeview Plaza Blvd Ste C Worthington Ohio 43085 USA...
