Specifications

11
START-UP AND OPERATION
Important: Minimum water supply pressure is 10 psi.
VAPORMIST DI
Make-up Water Piping
In this unit the electronic probe control is replaced by a
float valve and a float operated low water cut-off switch.
The basic water level system and circuit for heater
protection in the event of a low-water condition is
common to all DI humidifiers and can be found in the
wiring diagram located inside the removable front panel
on the right-hand side of the unit.
Control Circuit
a) Adjust humidistat to "call" setting.
b) Open shut-off valve on water supply line. Unit should
begin filling with water through the fill valve.
c) Shortly before the fill valve shuts off, the heater cut-
off switch will "make". When this switch makes, the
heating element contactor(s) will be actuated after a
ten-second delay. A time delay relay prevents
contactor chatter due to bouncing of heater cut-off
float.
d) Check heater cut-off circuit.
1. Close manual top valve on water supply.
2. Open ball valve and start draining unit.
3. When water level drops past switching level on
the heater cut-off float, the heating element
contactor(s) will drop out.
4. When step 3 has been satisfactorily completed,
close drain valve.
e) Check function of field-installed safety controls,
such as the fan proving switch. Contactor(s) should
drop out when any proving switch is "open".
f) Check heater draw by testing and recording voltage
and amperage in each phase. Readings should
match name plate readings; name plate is located on
the humidifier housing.
g) Inspect installations for steam or air leaks while
operating the VAPORMIST. Any leaks should be
sealed.
Test Cycling the Drain/Flush System
The timer board contains four pairs of terminal pins
which are marked 20, 40, 80 and “T” (TEST). To test:
1. Pull the pin block off the pair of pins in use, move it to
the “T” pair, and push it on.
2. Set the humidistat high enough so that unit will remain
“on call” for at least one hour.
3. After about 35 minutes of operation, a drain/flush
cycle will take place.
4. Once the test cycle is completed, move the pin block
back to the desired pair of pins. Failure to do so will
result in a drain/flush cycle every 35 minutes.
VAPOR-LOGIC
2
The VAPOR-LOGIC
2
key pad allows the adjustment of
surface water bleed-off amount to accommodate the
water condition. This adjustment varies the duration of
the overfill with each water fill cycle.
The adjustable skim time allows for an extended period
of time (2 to 40 seconds) to reduce mineral accumula-
tion. In addition to controlling the water level,
VAPOR-LOGIC
2
determines when the heaters are
energized. If there is a call for humidification, even
during the fill cycle, the heating elements will stay on to
provide continuous output.
For more information regarding the operation of
the VAPOR-LOGIC
2
microprocessor, see the
VAPOR-LOGIC
2
Installation Instructions and Mainte-
nance Operations Manual.
VAPORMIST
®
Make-up Water Piping
Use cold or hot make-up water. If the water pressure is
above 60 psi and/or water hammer would be objection-
able, a pressure-reducing valve or shock arrester should
be installed. Even though the VAPORMIST has an
internal 1" air gap, some local codes may require a
vacuum breaker.
VM-IOM-1996 Scan.pdf 11 11/19/2009 9:57:23 AM