Installation
TWRF1 SCR Power Controller
8
Ametek HDR Power Systems
Rev 2
2.4
Wiring Overtemperature Contacts
Normally-closed (N.C.) heat sink thermostats are standard on all fan-cooled models (rated 90 A and
higher). These thermostats, which close on high heat sink temperature (200 ºF), may be used to
initiate an alarm, shunt trip, or other device for SCR protection. Thermostat connections are on
terminals 23 and 24 as shown in Figure 2.1.
If desired, normally-open (N.O.) contacts may be substituted for the normally-closed (standard). Heat
sink thermostats are optional on units with current ratings lower than 60 amperes and can be ordered
with either N.O. or N.C. contacts
.
FAN POWER
120 Vac
(220 Vac
OPTIONAL)
OVER TEMP
N.O. STANDARD
(N.C. OPTIONAL)
21
22
23
24
Figure 2.1 Thermostat Connections
2.5
Command Signal Input
HDR’s TWRF Phase-Fired SCR Power Controllers are configured for a potentiometer (non-isolated)
but, has the capability of having either an isolated current or non-isolated voltage Command Signal
input. The standard input impedance is 500 ohms for isolated and 1500 ohms for non-isolated. The
potentiometer may by 500 Ω to 5 kΩ, and should be rated at 1/2 watt, minimum.
All units are equipped with DIP switches, select “isolated” position for a 4-20 mA command signal and
“non-isolated” for a voltage input such as 0-10 V dc. See Figure 2.2.
The isolated input works best with an offset Command Signal such as 4-20 mA; however, it will work
with both offset and zero based Command Signals. Zero based Command Signals may have a small
amount of non-linearity (input to output) at the low end. This should not be a problem on closed loop
systems.
Current Input
Voltage / Manual Pot Input
Figure 2.2 Isolated/Non-Isolated Switches
----
OP
EN
---
-
1
2
3
4
C1
C2
NO
N-I
SO
LA
TE
D-C
2
SW
2
IS
O
LA
TE
D-C
1
SW
1
Содержание TWRF1 SCR Series
Страница 6: ...Table of Contents TWRF1 SCR Power Controller iv Ametek HDR Power Systems Rev 2...
Страница 8: ...Safety Instructions TWRF1 SCR Power Controller 2 Ametek HDR Power Systems Rev 2...
Страница 12: ...Description TWRF1 SCR Power Controller 6 Ametek HDR Power Systems Rev 2...
Страница 16: ...Operation TWRF1 SCR Power Controller 10 Ametek HDR Power Systems Rev 2...
Страница 22: ...Operation TWRF1 SCR Power Controller 16 Ametek HDR Power Systems Rev 2...
Страница 33: ...TWRF1 SCR Power Controller Appendix Rev 2 Ametek HDR Power Systems 27 Appendix B 30 60 A Outline R...
Страница 34: ...Warranty TWRF1 SCR Power Controller 28 Ametek HDR Power Systems Rev 2 Appendix C 90 225 A Outline R...
Страница 35: ...Notes...
Страница 36: ...530 Lakeview Plaza Blvd Ste C Worthington Ohio 43085 USA...
