Manualshelf

Application Guide

ManualsBrandsHoneywell ManualsHVAC SuppliesSmart VFD HVAC Variable Frequency Drive, 208/230V, 2 HP, NEMA 1, Drive Alone
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63-7062 28
Equipment Categories
Non Sensitive
Equipment falling into this category are simple electromechanical device:
— Relays.
— Contactors.
— Electric motors.
— Solenoid devices.
Care Required
Many electronic devices are insensitive to VFD emissions due to the spectrum at which this interference is generated and the
ability for the target equipment to locally filter out the noise. Computers, and digital equipment generally working above 1 Vdc
should not normally suffer from these emissions, unless they have circuits within them or externally connected, which fall into
the following category. Many control systems have this combined categorization.
Sensitive
Any analog measuring circuit using low level signals:
— Thermocouples.
— Resistive temperature sensor.
— Humidity sensors.
— Strain gauges.
— pH sensors.
— Audio circuits.
— Proximity sensors.
Computer digital circuits, Ethernet and RS 232 have good immunity to VFD RFI, provided the cabling is correctly installed with
high quality screening.
Very Sensitive
Systems that are specifically designed to be sensitive to electromagnetic radiation the band 100 kHz to 5 MHz:
— Radios designed to work in the long wave and medium wave bands.
— Inductive-loop pagers and communication systems.
— Power line carrier systems.
Radio receivers with input filters and shielded cables have little chance of problems outside a 3 to 9 foot radius around the
system. Televisions, VHF radios, and mobile telephones using high frequencies are generally unaffected by VFD RFI.
General Wiring Standards
Sensitive equipment should not be installed within 1 foot of the VFD and its associated input and output cables. Parallel runs of
any control signal cables and the input and output cables should be avoided. Where this is not possible then the control cables
should be correctly shielded but not installed with 1 foot of the input and output cables of the VFD. See Fig. 32.
Input
Filter
R
S
T
P
G
M
O
N
P
A
R
R
E
F
B
T
N
S
R
U
N
R
E
A
D
Y
F
A
U
L
T
Honeyw ell
Fig. 32. Distances to keep as short as possible.