What is an ECM Motor?
ECMs will operate in the 80 per cent efficiency range at all speeds. A
An ECM is made up of two components; the motor
and a motor control module.
The motor control is what sets the ECM apart
from any other motor. Single-phase 120 or 208/240
AC power is supplied to the motor module, which
converts that voltage to three phase DC voltage.
The controller then sequentially energizes the three
motor phases at the appropriate time for optimum
operation. Additionally, the controller has the ability
to modulate speed.
The motor is a three-phase DC motor with a
permanent magnet rotor, which contributes to the
motor’s efficiency. While typical DC motors are
supplied with brushes to provide the commutation
(alternating the cycle), ECMs are brushless.The com
mutation is done electrically with the controller.
FIGU
EQUIPMENT DISTRIBUTED BY ECCO
WITH ECM MOTOR TECHNOLOGY:
• Armstrong Gas Furnaces
• Nortron Electric Furnace
• Lifebreath HRVs
• Lifebreath Clean Air Furnaces
Contact your local ECCO Sales Branch to
learn more about this energy saving
technology.
secondary benefit of the ECM is that it will generate less heat than its PSC
counterpart...meaning that there will be a slight reduction in the refrigeration
load too.
The benefit of using ECMs
FIGURE 1 TYPICAL MOTOR EFFICIENCY
becomes apparent when
FOR A 50W MOTOR
looking at the energy savings expressed monetarily.
The results shown in the
chart in Figure 2 are from a
test conducted by an independent lab to demonstrate
Shaded pole
Single phase
Three phase
ECM
capacitor
the energy savings from
using ECMs. The test was
conducted on a frozen food walk in utilizing a two fan evaporator, fitted with
two 1/15 hp shaded pole motors.
The- box was operated with the original shaded pole motors to establish
baseline data for comparison. Then the shaded pole motors were replaced
with ECMs, while retaining the original fan blades.
Measurements of the following were made for comparative purposes:
fan rotational speed using an electronic stroboscope, air flow using a vane
anemometer, evaporator discharge air temperature along with box temperature, and voltage, current, power, and cumulative energy data at 15 minute
intervals. The data speaks for itself. There is a 67 per cent reduction in power
FIGURE 2
FAN ENERGY USAGE AND OPERATING COST
consumption of the evaporator fans alone. The testing indicated that for every
two watts of evaporator fan motor power reduction experienced, a corresponding one watt of condensing unit power reduction would be experienced.
While the more sophisticated ECMs carry a higher price tag than shaded
pole or PSC motors, there is a great opportunity to reduce electrical consumption. Payback is in the 18-month range but one would logically expect that the
price will come down as their usage becomes more widespread.
From a broader perspective, each application that utilizes ECM technology
does its part to reduce the collective power generating needs for our planet,
thereby reducing potential climate altering emissions.
Dave Demma holds a degree in refrigeration engineering
and worked as a journeyman refrigeration technician before
moving into the manufacturing sector where he regularly
trains contractor and engineering groups. He can be reached
at ddemma@k-rp.com.
HPACMAG.COM