System Protection Features And Setup; Asd Protection; Motor Protection - Toshiba Q7 Installation And Operation Manual

System Protection Features and Setup

The Q7 ASD uses protection features that are designed to protect the ASD and to protect the motor from
overload/overcurrent damage. Because of the different types of abnormal conditions that may occur (e.g.,
inrush current, short circuit current, extended overloads, etc.), instantaneous and overcurrent protective
devices have ben provided. Both protection mechanisms require an application-specific adjustment for
performance optimization and the minimization of nuisance tripping.

ASD Protection

The Q7 ASD is designed and manufactured to accommodate a wide range of voltage and current
requirements; from the 0.75 HP to the 350 HP ASD (Typeform). Each ASD is equipped to operate at
100% output continuously and can operate at 110% for 60 seconds. A trip will be incurred if the design
specifications are exceeded for a given ASD.
ASD overload protection is accomplished via the ASD software which can be configured to disable the
system in the event of an overload. Using the Electronic Thermal Protection setting, the ASD may be
properly matched to the motor being driven and the application.
The short circuit protection, which is provided by hardware and software, disables the system in the event
of a fault.

Motor Protection

Motor circuit protection is accomplished using circuit breakers that have adjustable trip thresholds to
properly match the motor being driven and the application. The circuit breakers are set to the minimum
current value of the circuit breaker at the factory and must be set for the motor being used and to properly
match the requirements of the application.
The motor protection hardware is comprised of a Motor Circuit Protector (MCP) (see
11) at the 3-phase system input and an Overload Circuit Protector (OCP) connected to the motor (see
Figure 5 on pg.
MCP and the OCP circuit breakers.
Motor Protection
Read and understand all safety warnings before operating this equipment!
MCP Adjustment Setting
The trip threshold of the MCP is set to the lowest setting when the product ships from the factory. Refer to
NEC Table 430-152 for recommendations on establishing the proper MCP setting for a given application.
When using a Design E motor, the setting for the instantaneous trip circuit breaker shall not be more than
1100% of the full-load input current. The maximum setting for a motor, other than Design E, shall be
800% of the input current. This is done to ensure that the protection does not activate while starting the
motor, but is able to provide adequate protection for a fault condition.
10
12). See Figure 8 on pg. 18 for the schematic representation and electrical location of the
Q7 ASD Installation and Operation Manual
Figure 4 on pg.