Enviro VDD User Manual

ENVIRO-TEC
23
FORM ET115.24-NOM12 (718)
Risk of Electric Shock
Disconnect or isolate all power supplies before making electrical connections. More than one
disconnection or isolation may be required to completely de-energize equipment. Contact with
components carrying hazardous voltage can cause electric shock and may result in severe
personal injury or death.
No routine maintenance is required for the discrete components.
TABLE F.4 – FAN MOTOR CONTROL
Jumper Name Description
No 24VAC
power
No jumper between R
and G without external
start/stop control
installed
Verify that either an external start/stop or jumper between R and G is
installed. If neither, install one of them.
JP1 removed without
oat switch or low
temperature sensor
installed
Verify that either a oat switch, low temperature sensor or JP1 are
installed. If none, install one of them.
Float switch or low
temperature sensor
tripped
Verify oat switch and/or low temperature sensor (if present) are made.
Incorrect incoming line
voltage
Verify incoming voltage to the unit per unit nameplate. Supply voltage must
be within +/- 5% of unit nameplate..
Damaged transformer
Verify the secondary transformer voltage between R and S1 is 24VAC ± 10%.
If not, verify primary transformer voltage is within tolerance. If the primary
voltage is within tolerance and the secondary voltage is not, replace the
transformer.
Improper wiring
connections
Verify that the unit is wired per the unit wiring diagram for incoming voltage.
If the unit includes main fusing, verify that the fuses are not blown. Verify
wire harness connections are secure. See “Checking Wire Harnesses” section.
Fan motor
will not run
No 24VAC power See above.
Hand-Off-Auto (HOA)
switch is set to Off
Verify the HOA switch is not set to OFF.
Fan speed is not
commanded
Verify a fan enable is commanded from either jumper be-tween R and G, a
unit-mounted or remote-mounted three speed switch, or a thermostat.
Electric heat
signal is not
provided to
contactor
Fan speed is not
commanded
Verify that fan motor is running. A fan speed must be commanded to allow
the electric heat contactor to energize on a call for heat.

Enviro VDD Specifications

General

Brand	Enviro
Model	VDD
Category	Fan
Language	English