Twin City Electronically Commutated Motors - IM-4055 - Manual

IM-4055
April 2012
Electronically Commutated Motors
INSTALLATION, OPERATION & MAINTENANCE MANUAL
Electronically Commutated Motors
Electronic commutation (EC) is the latest motor technology to be used in direct drive fans. Also known in the indus-
try as Brush Free or Brushless DC, the EC motors utilize an electronic circuitboard to control the functionality of the
motor. The motor operates off of 115V AC single phase power, which is converted to DC power within the motor’s
circuitry. The result is a highly efficient motor with an expanded speed control range and a variety of speed control
options to choose from.
General Installation
CAUTION: Sheet metal parts, screws, clips and similar items inherently have sharp edges, and it is necessary that the
installer and service personnel exercise caution.
The installation of this equipment shall be in accordance with the regulations of authorities having jurisdiction and all
applicable codes.
This equipment is to be installed by an experienced installation company and fully trained personnel.
Verify that the wheel rotation is correct. It should be CW when viewed from the shaft end (CCW from opposite shaft end).
Refer to IM-4050, IM-4205 or IM-4800 for detailed installation instructions on the fans that utilize EC motors.
Do not operate the fan beyond the maximum cataloged RPM. The current should be verified any time the RPM is
adjusted to ensure it is below the nameplate amperage value.
Electrical Connection
1. Connect supply wiring to the disconnect switch (non-fused standard).
2. The motor is factory set at the voltage marked on the fan nameplate. Check the line voltage with the nameplate
voltage.
3. The main power wiring should be sized for the ampacity shown on the dataplate. Size wires in accordance with
the ampacity tables in Article 310 of the National Electrical Code. If long wires are required, it may be necessary to
increase wire size to prevent excessive voltage drop. Wires should be sized for a maximum of 3% voltage drop.
CAUTION: Use copper conductors only.
CAUTION: Protect wiring from sharp edges. Leave some slack in the line to prevent damage.
4. Disconnect switches are not fused. The power leads must be protected at the point of distribution in accordance
with the fan dataplate.
5. All units must be electrically grounded in accordance with local codes or, in the absence of local codes, with the
latest edition of the National Electrical Code (ANSI/NFPA 70). A ground lug is provided as standard in the unit ter-
minal box. Size grounding conductor in accordance with Table 250-95 of the National Electrical Code.
DO NOT use
the ground lug for connecting a neutral conductor.
6. Supply voltage to the power ventilator should not vary by more than 10% of the value indicated on the unit data-
plate. Phase unbalance must not exceed 2%.
©2012 Twin City Fan Companies, Ltd.