Allen-Bradley 23PFC, Руководство по обслуживанию оборудования

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28 Rockwell Automation Publication 23PFC-TG001A-EN-P - March 2018
Chapter 2 Component Test Procedures
10. With the digital multimeter set to “diode test”, measure each connection
point on the pulse transformer board that is listed in Table 6 .
11. If any of the actual measurements are out of tolerance, replace the pulse
transformer board.
Thermistors and Thermal
Switches One of these devices, which is connected to terminals 78 and 79 on the control
power terminal block, can detect an overheated load:
• An external, user-supplied thermistor (PTC)
• A thermal switch
• For frame A devices, see Figure 21 on page 132 for terminal block
location.
• For frame B devices, see Figure 23 on page 137 for terminal block
location.
A “PTC Over Temp” fault (F16) or alarm typically signal that the load is
overheating.
• See Alarm Descriptions in the PowerFlex DC Field Controller
Programming Manual, publication 23PFC-PM001 , for details.
• For frame A devices, see Figure 11 on page 125 for a circuit diagram.
• For frame B devices, see Figure 16 on page 127 for a circuit diagram.
Verify that the PTC or thermal switch is correctly configured:
• If a thermal switch is used, a 1 kΩ resistor must be placed in series
between the switch and either terminal 78 or 79.
• If a thermistor (PTC) or a thermal switch is installed, a 1 kΩ resistor
must be connected between terminals 78 and 79.
A bimetal thermostat monitors the field controller heat-sink temperature.
When the heat sink temperature is too high, a “Heatsink OvrTemp” fault (F8)
occurs.
• See Fault Descriptions in the PowerFlex DC Field Controller
Programming Manual, publication 23PFC-PM001 , for details.
• For frame A devices, see Figure 12 on page 125 for a circuit diagram.
• For frame B devices, see Figure 17 on page 128 for a circuit diagram.
During normal operation, 1.6V DC is present between terminal 78 and device
common. When an open circuit exists between terminals 78 and 79, 24V DC
will be present at terminal 78 to device common. If the 24V is missing, the
pulse transformer board can require replacement.
Table 6 - Load Pulse Transformer Primary Measurements
For SCR (+) Meter Lead (-) Meter Lead Meter reading Connector XY Pinout
1/01 XY-8 XY-1 0.41 Ω
4/04 XY-8 XY-4
2/02 XY-8 XY-2
5/05 XY-8 XY-5
3/03 XY-8 XY-3
6/06 XY-8 XY-6
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