M248, Oval coolBLUE Inductive Absorber , VFD 1632Hp and above, 300x254x30MM

M111, Oval coolBLUE Inductive Absorber , VFD 429-1632Hp, 250x220x30MM

KEY FEATURES

• Product type: Common mode choke (inductive absorber) designed to mitigate VFD-induced motor bearing currents

• Model: CoolBLUE® M-248 – Oval core version, electrically equivalent to round cores, optimized for easier mechanical installation

• Application range: VFD-driven motors 1632 HP and above

• Function: Absorbs high-frequency common mode currents generated by VFDs before they reach motor bearings

• Protection benefits: Reduces bearing fluting, frosting, EDM damage, lubrication breakdown, and premature bearing failure

• System role: Operates as a common mode choke when multiple cores are installed in series on inverter output cables

• Installation location: Must be installed on the load side of the VFD (inverter output); cabinet installation preferred when possible

• Installation method: Power cables pass through the core; multiple cores installed in series based on cable length requirements

• Thermal rating: Normal operation below 158°F / 70°C; correct number of cores required to prevent magnetic saturation

• Maintenance: No maintenance required; solid-core construction designed for long-term, lifetime service

• Reliability advantage: Eliminates wear and maintenance issues associated with shaft grounding rings, brushes, corrosion, and contamination

• Typical applications: Very large industrial drives, heavy-duty pumps and fans, power generation systems, heavy manufacturing, renewable energy installations, and critical infrastructure

QUANTITY GUIDELINE – COOLBLUE® M-248

• Applicable motor range: 1632 HP and above

• Cable length: up to 150 ft / 50 m
– 4 cores

• Cable length: up to 300 ft / 100 m
– 4 cores

• Cable length: up to 450 ft / 150 m
– 6 cores

• Cable length: up to 900 ft / 300 m
– 8 cores

• System function:
– Multiple cores installed in series operate as a common mode choke on the inverter output

• Thermal consideration:
– Normal operation below 158°F / 70°C
– Correct quantity is critical to prevent magnetic saturation and overheating

• Installation location:
– Must be installed on the load side of the VFD (inverter output) only

• Installation note:
– Oval core design allows easier mechanical installation with equivalent electrical absorption to round cores

CoolBLUE® toroids made from the nanocrystalline material NANOPERM® are
being used increasingly to reduce damaging motor bearing currents in modern
high power inverter systems operating at high switching frequencies. As a result of
these unwanted currents, the bearings corrugate, leading to electrical breakdown
in the lubrication and finally to a standstill of the entire motor.
The use of CoolBLUE® cores not only significantly reduces the over voltage peaks
at the motor terminals, but also suppresses the asymmetrical EMI currents which
are generated by the parasitic capacities of the motor itself together with the motor
cable. In order to achieve an efficient reduction in these destructive effects, one or
more CoolBLUE® cores of suitable geometry have to be placed together over the
connector cables in the DC-link as well as at the inverter output. In this configura-
tion, the cores operate as a common-mode choke.