Relay outputs, Thermistors and thermal switches, Relay outputs thermistors and thermal switches – Rockwell Automation 23P PowerFlex Digital DC Drive User Manual
Page 62
62
Rockwell Automation Publication 20P-UM001K-EN-P - July 2014
Chapter 1
Installation and Wiring
Relay Outputs
Terminals 35 and 36 and 75 and 76 are N.O. relay outputs. The relay output
between terminals 35 and 36 is configured with parameter
[Relay Out 1 Sel]. The relay output between terminals 75 and 76 is configured
with parameter
[Relay Out 2 Sel]. See Contactors on page
for more
information.
Note: If external contactor coil current ratings are greater than 1 amp, use an
interposing relay between the drive relay 1 or relay 2 output and the contactor
coil.
Thermistors and Thermal Switches
To detect motor overheating and protect the motor from overloading, an
external, user-supplied thermistor (PTC) or thermal switch must be connected
to terminals 78 and 79. The drive’s response to a motor over temperature fault is
configured in parameter
[OverTemp Flt Cfg]. If a thermistor or thermal
switch is not used, a 1 k
Ω
resistor must be connected between terminals 78 and
79 (installed at the factory). Follow the appropriate instructions below when
installing a thermal sensor.
Thermistors (PTC)
PTC thermistors fitted in the motor can be connected directly to the drive via
terminals 78 and 79. In this case the 1 k
Ω
resistor is not required between
terminals 78 and 79.
Thermal Switches (Klixon
®
) in the Motor Windings
“Klixon” type temperature-dependent contacts can disconnect the drive from the
motor via an external control or can be configured as an external fault by using a
digital input on drive. They can also be connected to terminals 78 and 79 to
indicate a drive “Motor Over Temp” fault (F16), though this is not
recommended due to the noise sensitivity of the current threshold circuitry. If a
thermal switch is used a 1 k
Ω
resistor must be placed in series between the switch
and one of the terminals.
Terminals
Description
Maximum
Voltage
Maximum
Current
35, 36
Normally open contact. Configured with parameter 1392 [Relay Out 1
Sel], set to 25 “Contactor” by default.
250V AC
1 A
75, 76
Normally open contact. Configured with parameter 629 [Relay Out 2
Sel], set to 5 “Ready” by default.
78, 79
Motor thermistor (PTC) or thermal switch connections