Low Voltage Control Wiring; Circulating Air And Filters; Ducting; Condensate Drain Piping - Daikin M Series Installation Instructions Manual

nuts) to prevent water leakage into building. All required
conduit and fittings are to be field supplied.
Supply voltage to roof top unit must not vary by more than
10% of the value indicated on the unit data plate. Phase
voltage unbalance must not exceed 2%. Contact your
local power company for correction of improper voltage or
phase unbalance.
HIGH VOLTAGE ENTRANCE
(REMOVE PLUG)
LOW VOLTAGE
RETURN
POWER THRU
THE CURB
47-9/16"
electrical entrance and thru curb
(bottom view of unit)

Low Voltage Control Wiring

1. A 24V thermostat must be installed for unit operation.
2. Locate thermostat or remote sensor in the
conditioned space where it will sense average
temperature. Do not locate the device where it may
be directly exposed to supply air, sunlight or other
sources of heat. Follow installation instructions
packaged with the thermostat.
3. Use #18 AWG wire for 24V control wiring runs not
exceeding 75 feet. Use #16 AWG wire for 24V
control wiring runs not exceeding 125 feet. Use #14
AWG wire for 24V control wiring runs not exceeding
200 feet. Low voltage wiring may be National
Electrical Code (NEC) Class 2 where permitted by
local codes.
4. Route thermostat wires from sub-base terminals
to the unit. Control wiring should enter through the
condenser panel opening or through curb indicated
in "Electrical Entrance" figure. Connect thermostat
and any accessory wiring to low voltage terminal
block TB1 in the main control box.
NOTE: Field-supplied conduit may need to be
installed depending on unit/curb configuration.
19-3/8
31-3/8
ENTRANCE
4-1/16 DIA.
4-1/2"
7-1/2"
Use #18 AWG solid conductor wire whenever
connecting thermostat wires to terminals on
sub-base. DO NOT use larger than #18 AWG wire.
A transition to #18 AWG wire may be required
before entering thermostat sub-base.
NOTE: Refer to unit wiring diagrams for
thermostat or remote sensor connections.

CIRCULATING AIR AND FILTERS

Ducting

Ducting work should be fabricated by the installing
contractor in accordance with local codes. Industry
manuals may be used as a guide when sizing and
designing the duct system-such as NESCA (National
Environmental Systems Contractors Association, 1501
Wilson., Arlington, Virginia 22209).
The unit should be placed as close as possible to the
space to be air-conditioned allowing clearance dimensions
as indicated. Ducts should run as directly as possible
to supply and return outlets. Use of non-flammable
weatherproof flexible connectors on both supply and return
connections at the unit to reduce noise transmission is
recommended.

CONDENSATE DRAIN PIPING

The condensate drain connection of the evaporator is a
¾" NPT half coupling. A trap must be provided to have
proper condensate draining. Install condensate drain trap
as shown in FIGURE 9: CONDENSATE DRAIN TRAP
PLUMBING. Ensure drain connection is 3/4" or larger. Do
not operate unit without trap and ensure unit is level or
slightly inclined toward drain.
DRAIN
CONNECTION
UNIT
FLEXIBLE
TUBING-HOSE
OR PIPE
A POSITIVE LIQUID
SEAL IS REQUIRED
drain connection

Horizontal Drain

Drainage of condensate directly onto the roof may be
acceptable; refer to local code. It is recommended that a
small drip pad of either stone, mortar, wood or metal be
provided to prevent any possible damage to the roof.

Vertical Drain

To use the bottom drain connection, remove the drain plug
from the bottom connection and install it in the horizontal
connection.
10
2" MINIMUM
3" MINIMUM