Hi Magnetited, You are Right IEEE 841(Mill & Chemical) are high efficiency totally enclosed fan-cooled(TEFC) or non -ventilated up to 4160 Volts and Up to 500 HP. from the 841´s point of view this motor is out of specification, maybe your costumer wants an electrical motor WPII 4 KV 575 HP that meets IEEE841 and this is a special motor.
A short IEEE 841 Standard:
Electrical
designed to meet NEMA MG-1, MG-13 and IEEE 841
90°C rise by resistance method at 1.15 S.F. (or 80°C rise by resistance method at 1.00 S.F.)
motors between 2300V and 4160V use VPI form windings that withstand a surge of 3.5 per unit voltage at a rise time of 0.1 – 0.2ms and 5 per unit voltage at a rise time of 1.2ms or longer
1.15 Service Factor rating
rated for ambient temperature from -25°C to +40°C
3 Leads c/w solderless lug terminals
copper cage rotor construction
NEMA Design B as defined in section 1.17.1.2 of NEMA MG 1-1993
have a nonhygroscopic, chemical and humidity resistant class F insulation system
Mechanical
IP54 rated enclosure
IP55 rated main conduit box with twice the volume specified in NEMA
IP55 rated bearing protection (320T frame and larger)
all ratings are designed for bi-directional rotation
cast iron frame, brackets, hoods and conduit box
frame provided with two (2) threaded drain holes c/w drain plugs and tapped hole on foot for ground lug
foot flatness and shaft runout meet or exceed IEEE 841
automatic corrosion-resistant, replaceable drain plugs
exterior paint consists of one (1) coat zinc chromate epoxy primer and (1) coat of dark blue paint
F-1/F-2 interchangeability
non-sparking plastic or bronze fan
noise level not to exceed 90dB "A"
dynamically balanced rotor designed not to exceed 0.08 inches/second
regreasable bearings with an AFBMA C3 clearance and they are supplied with a rust-inhibiting grease which provides a minimum L-10 life of 30,000 hrs
bearing temperature rise of 50°C for all 2 pole motors and 45°C for all 4 and 6 pole motors.
Regards
PETRONILA