Hitachi SJ7002 Series Instruction Manual page 187

Thermistor
Motors that are equipped with a thermistor can be protected from overheating. Input terminal
[TH] is dedicated to sense thermistor resistance. The input can be set up (via B098 and B099)
Thermal
to accept a wide variety of NTC or PTC type thermistors. Use this function to protect the motor
Protection
from overheating.
—
Opt. Code
When a thermistor is connected between terminals [TH]
and [CM1], the inverter checks for over-temperature and
[TH]
Symbol
will cause a trip (E35) and turn OFF the output to the
motor. Be sure the thermistor is connected to terminals
Valid for
[TH only]
[TH] and [CM1]. If the resistance is above or below
Inputs
(depending on whether NTC or PTC) the threshold the
Required
B098, B099,
inverter will trip. When the motor cools down enough, the
and C085
Settings
thermistor resistance will change enough to permit you to
clear the error. Press the STOP/Reset key to clear the error.
Default
[TH]
terminal
An open circuit in the thermistor causes a trip, and the
inverter turns OFF the motor output.
Three-wire
The 3-wire interface is an industry standard motor control interface. This function uses two
inputs for momentary contact start/stop control, and a third for selecting forward or reverse
Interface
direction.
Operation
20=[STA]
Opt. Code
21=[STP]
and
Symbol
22=F/R
Valid for
[1] to [8]
Inputs
Required
A002=01
Settings
To implement the 3-wire interface, assign 20 [STA] (Start), 21 [STP] (Stop), and 22 [F/R]
Default
Requires
config. (Forward/Reverse) to three of the intelligent input terminals. Use momentary contacts for Start
terminal
and Stop. Use a selector switch, such as SPST for the Forward/Reverse input. Be sure to set the
operation command selection A002=01 for input terminal control of motor. Note the following:
• If you have a motor control interface that needs logic-level control (rather than momentary
• The STP logic is inverted. Normally the switch will be closed, so you open the switch to
• When you configure the inverter for 3-wire interface control, the dedicated [FW] terminal is
The diagram below shows the use of 3-wire control. STA (Start Motor) is an edge-sensitive
input; an OFF-to-ON transition gives the Start command. The control of direction is level-
sensitive, and the direction may be changed at any time. STP (Stop Motor) is also a level-
sensitive input.
Symbol Function Name
STA Start Motor
STP Stop Motor
F/R Forward/Reverse
pulse control), use the [FW] and [RV] inputs instead.
stop. In this way, a broken wire causes the motor to stop automatically (safe design).
automatically disabled. The [RV] intelligent terminal assignment is also disabled.
[STA] terminal
[STP] terminal
[F/R] terminal
Motor revolution speed
TH
TH
P24 PLC
thermistor
Description
Start motor rotation on momentary contact (uses accel-
eration profile)
Stop motor rotation on momentary open (OFF is active
state), (uses deceleration profile)
ON = Reverse; OFF = Forward
Forward
4–25
SJ700 Inverter
2
FW CM1
8 5 3 1
CM1
7 6 4 2
Motor
Reverse
t