8.4 Installing Peripheral Devices Low Speed Operation and Motor Thermal oL Relays Generally, thermal relays are applied on general-purpose motors. When general-purpose motors are driven by AC drives, the motor current is approximately 5 ~ 10% greater than if driven by the commercial power supply. In addition, the cooling capacity of a motor with a shaft-driven fan decreases when operating at low speeds. Even if the load current is within the motor rated value, motor overheating may occur. A thermal relay cannot effectively protect the motor due to the reduction of cooling at low speeds.
For this reason, apply the UL recognized electronic thermal overload protection function built into the drive whenever possible. UL recognized electronic thermal overload function of the drive: Speed-dependent heat characteristics are simulated using data from standard motors and force-ventilated motors. The motor is protected from overload using this function. Using One Drive with Multiple Motors Turn off the electronic thermal overload function. Please refer to the appropriate product instruction manual to determine which parameter disables this function. The UL recognized electronic thermal overload function of the drive cannot be applied when using multiple motors on one drive.
Long Motor Cables When long motor cables and high carrier frequency are used, nuisance tripping of the thermal relay may occur due to increased leakage current. Therefore, reduce the carrier frequency or increase the tripping level of the thermal overload relay. Nuisance Tripping Resulting from High AC Drive Carrier Frequency Current waveforms generated by high carrier frequency PWM drives tend to create additional temperature rise in overload relays. Therefore, it may be necessary to increase the trip level setting when encountering nuisance triggering of the relay. WARNING! Fire Hazard.
Confirm an actual motor overload condition is not present prior to increasing the thermal oL trip setting. Check local electrical codes before making adjustments to motor thermal overload settings. u NEMA Type 1 Kit WARNING! Fire Hazard. Provide sufficient cooling when installing the drive inside an enclosed panel or cabinet. Failure to comply could result in overheating and fire. When multiple drives are placed inside the same enclosure panel, install proper cooling to ensure air entering the enclosure does not exceed 40 °C. The optional NEMA Type 1 kit can be installed to raise the enclosure protection level of an IP20/Open-Chassis drive to NEMA Type 1.
Drives with a NEMA Type 1 kit cannot be installed using side-by-side mounting unless the top cover is removed. The drive does not retain NEMA Type 1 integrity with the top cover removed. Refer to Installation Orientation and Spacing on page 27 for installation instructions. n Installation Environment Table 8.2 Installation Environment n Exterior and Mounting Dimensions for NEMA Type 1 Kit The following table matches each drive model with its appropriate drawing.
Table 8.3 Drive Models and Types 156 SIEP C710606 33A OYMC AC Drive – J1000 User Manual Environment Conditions Ambient Temperature -10 °C to +40 °C (NEMA Type 1/wall-mounted enclosure) Drive reliability improves in environments without wide temperature fluctuations. When using an enclosure panel, install a cooling fan or air conditioner in the area to ensure that the air temperature inside the enclosure does not exceed the specified levels. Do not allow ice to develop on the drive. Refer to Installation Environment on page 26 for all other installation environment specifications.
Protective Design Drive Model JZA Page Single-Phase 200 V Class Three-Phase 200 V Class Three-Phase 400 V Class NEMA Type 1 B0P1 B0P2 B0P4 20P1 20P2 20P4 – 157 B0P7 B1P5 20P7 21P5 22P2 24P0 40P2 40P4 40P7 41P5 42P2 43P0 44P0 157