Daikin Rebel Applied DPSA, Installation And Start-Up Manual

Page: 63 / 162

Unit Operation
www.DaikinApplied.com 63 IM 1287-4 • REBEL APPLIED ROOFTOP
added condensation losses. Whenever possible, use
insulated copper piping. Flexible steam hose should
be used for short runs (up to 15 feet or 5m) or for
interconnecting between the rigid pipe runs. For longer
runs, please consult the factory.
4. Whenever using rigid copper pipe, use insulation to
diminish condensation build up.
Single steam outlet
• Run one steam line from the steam outlet of the
evaporation chamber of the humidifier to the Multi-Steam
header (a reducer is welded at the inlet of the Multi-
Steam header).
• Use steam hose and clamps to make the connection from
hard insulated copper pipe to the Multi-Steam and the
humidifier.
IMPORTANT
Never reduce the diameter of the steam lines. Improper size will over-
pressurize the humidifier.
Condensate drain outlet
The Multi-Steam has a 1/2” (15mm) or 3/4” (20mm) NPT (or
BSPT) condensate drain connection.
IMPORTANT
Remove the 1/2” (15mm) or 3/4” (20mm) cap (shipping protection)
from the condensate drain before the installation.
• Run a pipe (same size as the condensate drain
connection) as directly as possible from the condensate
drain outlet to the floor drain with a proper slope and
install a steam trap to prevent any steam leakage from
the drain.
• The steam trap (S Type) should be installed higher than
the static pressure of the system by at least 2 inches
(51mm).
Start-up procedure
Follow this start-up procedure to avoid improper system
operation:
1. Ensure that plumbing connections have been done in
accordance with the instructions in this manual.
1. Verify that the steam supply line is connected properly to
the Multi-Steam.
2. Verify that the Humidifier Grid is properly pitched.
3. Verify that the Humidifier Grid condensate drain is
connected to the drain line.
Maintenance
• Inspect the Multi-Steam at startup and during normal
operation.
• Make sure all hose connections are secure and there are
no leaks in the line.
Troubleshooting
Problem Causes Corrective Actions
Multi-Steam discharges water
inside the duct or AHU
• Steam supply line is not
insulated.
• Steam supply line is not
properly drained or sloped.
• The Multi-Steam
condensate drain is blocked
or drain line is not properly
sloped.
• The Multi-Steam is not
properly pitched.
• Steam or condensate is
leaking from the gasket on
the Multi-Steam collapsible.
• Insulate the steam supply
line.
• Install steam trap to remove
the condensate from the
steam supply line.
• Slope the steam supply line
properly as per instruction.
• Verify the condensate
drain line.
• Pitch the Multi-Steam as per
instructions in Fig. Figure 98
and Figure 99
• Replace the gasket (p/n
SP 6867).
Problem Causes Corrective Actions
M
ulti
-S
teaM diSchargeS water
inSide the duct or
ahu
Steam supply line is not
insulated.
• Steam supply line is not
properly drained or sloped.
• The Multi-Steam
condensate drain is
blocked or drain line is not
properly sloped.
• The Multi-Steam is not
properly pitched.
• Steam or condensate is
leaking from the gasket on
the Multi-Steam collapsible.
VAV Box Output
In the Heating state, the VAV Output is turned OFF to indicate
that hot air instead of the normal cool air is being supplied to
the VAV boxes. The VAV boxes are driven to their Heating
Position when hot air is provided based on either the normally
open or normally closed contacts of the VAV output. The VFD
will continue to be controlled to maintain the desired duct
static pressure. This output is also OFF when the unit is in
the Startup or Recirculation states. If this output is in the Heat
(OFF) position when the unit enters the Fan Only state or
Minimum DAT Control state, the output remains OFF for an
adjustable Post Heat Time (while the unit VFDs are driven to
minimum speed) or until the VFD gets to its minimum speed if
the Post Heat Time is set greater than 0. The Post Heat Timer
can be adjusted via the keypad/display Timer Setting menu in
the Extended Menus.
During unoccupied operation, the VAV Box Output is in the
Cool (ON) position unless airflow is detected. When airflow is
detected, it switches to the Heat (OFF) position.