Hitachi Sj7002 Owners Manual

Using Intelligent Input Terminals
Operations
and Monitoring
4–20
Two - s t ag e
Acceleration and 
Deceleration   When terminal [2CH] is turned ON, the 
inverter changes the rate of acceleration and 
deceleration from  the initial settings (F002 
and F003) to use the  second set of accelera-
tion/deceleration values (A092 and A093). 
When the terminal is turned OFF, the 
inverter returns to the original acceleration 
and deceleration time (F002 acceleration 
time 1 and F003 deceleration time 1). Use 
A092...

SJ7002 Inverter
Operations
and Monitoring
4–21
External Trip   When the terminal [EXT] transitions OFF-to-ON,  the inverter enters the trip state, indicates 
error code E12, and stops the output. This is a  general purpose interrupt type feature, and the 
meaning of the error depends on what you connect  to the [EXT] terminal. Even if [EXT] is 
turned OFF, the inverter remains in the trip stat e. You must reset the inverter or cycle power to 
clear the error, returning the inverter to the Stop Mode.
In...

Using Intelligent Input Terminals
Operations
and Monitoring
4–22
 When the Run command is active immediately after the power is turned ON, a USP error  will occur. When this function is used, wait  for at least three (3) seconds after powerup 
before applying a Run command.
Commercial 
Power Source 
Enable   The commercial power source switching function is  useful in systems with excessive starting 
torque requirements. This feature permits the mo tor to be started “across the line,” sometimes 
called a...

SJ7002 Inverter
Operations
and Monitoring
4–23
Switching to inverter control occurs after the mo tor is running at full speed. First, Mg2 relay 
contacts open. Then about 0.5 to 1 seconds later, relay Mg3 contacts  close, connecting the 
inverter to the motor. The following timing diagram shows the event sequence:
In the previous timing diagram, when the mo tor has been started across the line, Mg2 is 
switched OFF and Mg3 is switched ON. With the Forward command to the inverter already 
ON, the [CS]...

Using Intelligent Input Terminals
Operations
and Monitoring
4–24
Analog Input 
Current/Voltage 
Select   The [AT] terminal operates in c onjunction with parameter setting A005 to determine the analog 
input terminals that are enabled for current or  voltage input. Setting A006 determines whether 
the signal will be bipolar, allowing for a reverse direction range. Note th at current input signal 
cannot be bipolar and cannot reverse direction  (must use [FW] and [RV] command with current 
input...

SJ7002 Inverter
Operations
and Monitoring
4–25
Thermistor 
Thermal
Protection   Motors that are equipped with a thermistor ca n be protected from overheating. Input terminal 
[TH] is dedicated to sense ther mistor resistance. The input can be set up (via B098 and B099) 
to accept a wide variety of NTC  or PTC type thermistors. Use this function to protect the motor 
from overheating.
When a thermistor is connected between terminals [TH] 
and [CM1], the inverter checks for over-temperature and 
will cause...

Using Intelligent Input Terminals
Operations
and Monitoring
4–26
PID Disable
and PID Clear   The PID loop function is useful for controlling  motor speed to achieve constant flow, pressure, 
temperature, etc. in many process applications. 
PID Disable –  This function temporarily suspends PID  loop execution via an intelligent input 
terminal. It overrides the parameter A071 (PID  Enable) to stop PID execution and return to 
normal motor frequency output char acteristics. the use of PID Disable on an...

SJ7002 Inverter
Operations
and Monitoring
4–27
The speed control mode is normally proportional-
integral compensation (PI), which attempts to 
keep the deviation betwee n the actual speed and 
speed command equal to zero. You can also select 
proportional (P) control function, which can be 
used for  droop control (i.e. several inverters 
driving one load).  Droop is the speed difference 
resulting from P control versus PI control at 100% 
output torque as shown in the graph. Set the P/PI 
switching...

Using Intelligent Input Terminals
Operations
and Monitoring
4–28
Remote Control 
Up and Down 
Functions   The [UP] [DWN] terminal functions can adjust the output frequency for remote control while 
the motor is running. The acceleration time and deceleration time used with this function is the 
same as for normal operation ACC1 and DEC1  (2ACC1,2DEC1). The input terminals operate 
as follows:
In the graph below, the [UP] and [DWN] terminals activate while the Run command remains 
ON. The output frequency...

SJ7002 Inverter
Operations
and Monitoring
4–29
Overload
Restriction   The inverter constantly moni tors the motor current during  acceleration, deceleration, and 
constant speed. If the inverter reaches the ove rload restriction level, it adjusts the output 
frequency automatically to limit the amount of  overload. This function prevents an over-current 
trip by inertia during rapid acce leration or large changes in load  at constant speed. It also 
attempts to prevent an over-voltage trip on dece...