Crane Duty Motors

Operating Conditions

The standard operating conditions for the crane duty motors are:

Voltage :  415 ± 10% Volts
Frequency :  50 ± 5 % Hz
Combined :  ± 10 %
Ambient Temperature  :  450 C
Altitude :  Upto 1000 m above mean sea level

In case any operating conditions are different than above, please contact nearest branch office of Havells India Ltd.

Electrical Design

Winding

All crane duty motors are manufactured using dual coat class F copper wire (with temperature withstand up to 1550C) as standard.

Insulation

The motors are having class F insulation with temperature rise limited to Class B. The motors are impregnated in a computerized impregnation plant that ensures high quality of impregnation with high varnish retention.

Deration for Higher Ambient & Altitude

For selection of motors for higher ambient and altitude, the rated kW should be reduced by the following factors for the frame selection.

Ambient 450C 500C 550C 600CFactor 100% 95% 90% 80%Altitude 1000m 1500m 2000m 2500m  3000mFactor 100% 95% 92% 88%  84%

Intermittent Duty Application

The motors are designed for intermittent duty operations and different starts/stops per hour as shown in the rating charts. The frame selections are based considering load GD2 values referred to motor shaft are less than or equal to motor GD2 values. Various intermittent duty types are explained below.

Short Time Duty - S2 Duty

The motor operates at constant load for a given duration which is less than that required to reach thermal equilibrium and is followed by a rest or de-energized period such that the motor cools down to close to ambient temperature.

The recommended values for the short time duty are 10, 30, 60 and 90 minutes.

Intermittent Periodic Duty with Starting- S3 Duty

The operation cycle consists of operation at constant load followed by a rest and de-energized period. The duty cycle is such that thermal equilibrium is not reached during one periodic cycle.

Intermittent Periodic Duty with Starting-  S4 Duty

In this duty cycle, each cycle consist of a period of starting, a period of operation at constant load followed by a rest and de-energized period. The duration of one cycle is so short that thermal equilibrium is not reached during one duty cycle.

Construction

Crane Duty Motors are available in Aluminum/ Cast Iron frames. Frames 80 & 90 shall also be available in Cast Iron on request.For higher frames, kindly refer to nearest branch office.

Enclosure

All motors are Totally Enclosed Fan Cooled (TEFC) as per IS 4691 and are suitable to operate in both outdoor and indoor applications.

Cooling

The motors are designed with IC0141 method of cooling as per IS 6362 which provides excellent heat dissipation of the motors and ensures longer life of the motor.

Degree of Protection

Degree of protection for machines are designated in accordance with IS 4691 by letter IP followed by two characteristic numerals corresponding to protection from dust and water. All motors are provided with IP55 degree of protection as a standard and are suitable for operation in dusty and humid environment conditions. Bearing DetailsAll motors are fitted with deep groove ball bearings with C3 clearance and greased for life ensuring longer trouble free operation.

Terminal Box

Terminal box is provided on top as a standard.