Metek TWRF1 SCR Series, Instruction, Operation And Maintenance Manual

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TWRF1 SCR Power Controller Description
Rev 2 Ametek HDR Power Systems 5
Table 1.3 General Specifications of TWRF1 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 1.2)
Thermostat contact rating: 120 Vac, 5 A; resistive
Input Signal:
Non-isolated
Isolated 0 to 1.5 V (min); 0 to 10 V (max) - Standard
0 to 6 mA (min); 0 to 20 mA (max)
Control methods: 1. Potentiometer, 5 kΩ, 1/2 watt (Customer-supplied) - Standard
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. – OPTIONAL
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.
Miscellaneous:
Phase-firing timebase 0º to 180º conduction per SCR
Controls: ZERO and SPAN potentiometers; 10-turn, screwdriver-adjustable.
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
30 through 60 A
90 through 225 A
lbs
6
18
kg
2.7
8.2
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 TWRF1 should be tested or operated with an adequate load since an open output will have line
voltage at the load connections.