26
D.
ELECTRICAL WIRING
WARNING! THE FOLLOWING SAFETY PRECAUTIONS MUST BE OBSERVED
a.
Electric rotating machinery and high voltage can cause serious or fatal injury if
improperly installed, operated or maintained. Responsible personnel must be
familiarized with the installation of electric motors and generators, the National
Electric Code, NFPA and all local safety requirements.
b.
All interconnecting of wiring for motors and accessory devices must be in strict
accordance with the National Electric Code, NFPA and applicable local codes.
c.
When installing or servicing, all power sources to the motors and accessory
devices must be de-energized and disconnected (lockout/tagout) and all moving
parts must be at a standstill.
d.
Safeguard or protective devices must not be bypassed or rendered inoperable.
1.
All electric motors are wired per the National Electrical Code. The rated conditions of
operation for the motor are as shown on the motor nameplate.
2.
Refer to the radiator assembly drawing for the correct fan rotation and air flow
direction. Check direction of rotation. If rotation must be changed, allow the motor
to stop completely, disconnect power (lockout/tagout) and then interchange any two
leads of a 3-phase motor.
3.
Dual voltage and single voltage motors can be connected for the desired voltage by
following the connection diagram shown on the motor nameplate or inside the motor
conduit box. Motors must be wired for across the line unless using a Wye-Delta
starter, then wire for Wye Start – Delta Run. For any special motors, contact Rocore
Engineering.
4.
CAUTION! Motor damage will occur if the motor is wired incorrectly.
5.
CAUTION! Make sure that the power source voltage matches the motor
nameplate voltage.
6.
WARNING! Disconnect all power sources before initiating any wiring,
maintenance or repair.
7.
WARNING! Make sure unit is electrically grounded in accordance with code
requirements.
8.
For VFD motor applications, note the following maximum turndown limitations for
the different types of motors. Exceeding these limits will result in motors overheating
and premature motor failure and will not be covered by Rocore’s warranty.
a.
Standard TEFC motors: 5:1
b.
Hi-Efficiency TEFC motors: 10:1
c.
TEAO motors for blower fan applications: 2:1
More than 4:1 turndown can cause motor noise. This can be eliminated or reduced
by some VFD settings. Refer to your VFD User’s Manual.