Thermal Insulation Of Refrigerant Piping; Wiring; Caution; Control Box And Connecting Position Of Wiring - Mitsubishi Electric CITY MULTI PURY-P-YEM-A Installationshandbuch

ant by turning the cylinder upside-down as shown below. If the cylinder has a
syphon pipe like that shown in the figure at the right, the liquid refrigerant can
be charged with the cylinder standing upright. Therefore, give careful attention
to the cylinder specifications. If the unit should be charged with gas refrigerant,
replace all the refrigerant with new refrigerant. Do not use the refrigerant re-
maining in the cylinder.
[Fig. 8.3.3] (P.3)
<In case of the cylinder having no syphon pipe.>
A Syphon pipe

8.4. Thermal insulation of refrigerant piping

Be sure to give insulation work to refrigerant piping by covering liquid pipe and gas
pipe separately with enough thickness heat-resistant polyethylene, so that no gap
is observed in the joint between indoor unit and insulating material, and insulating
materials themselves. When insulation work is insufficient, there is a possibility of
condensation drip, etc. Pay special attention to insulation work to ceiling plenum.
[Fig. 8.4.1] (P.4)
A Steel wire
C Asphaltic oily mastic or asphalt
E Outer covering B
Glass fiber + Steel wire
Heat
insulation
Adhesive + Heat - resistant polyethylene foam + Adhesive tape
material A
Indoor Vinyl tape
Outer
Floor exposed Water-proof hemp cloth + Bronze asphalt
covering B
Outdoor Water-proof hemp cloth + Zinc plate + Oily paint

9. Wiring

9.1. Caution

1 Follow ordinance of your governmental organization for technical standard re-
lated to electrical equipment, wiring regulations and guidance of each electric
power company.
2 Wiring for control (hereinafter referred to as transmission line) shall be (5 cm or
more) apart from power source wiring so that it is not influenced by electric
noise from power source wiring. (Do not insert transmission line and power
source wire in the same conduit.)
3 Be sure to provide designated grounding work to outdoor unit.
4 Give some allowance to wiring for electrical part box of indoor and outdoor
units, because the box is sometimes removed at the time of service work.
5 Never connect the main power source to terminal block of transmission line. If
connected, electrical parts will be burnt out.
6 Use 2-core shield cable for transmission line. If transmission lines of different
systems are wired with the same multiplecore cable, the resultant poor trans-
mitting and receiving will cause erroneous operations.
7 Only the transmission line specified should be connected to the terminal block
for outdoor unit transmission.
(Transmission line to be connected with indoor unit : Terminal block TB3 for
transmission line, Other : Terminal block TB7 for centralized control)
Erroneous connection does not allow the system to operate.
8 In the case of connecting with an upper class controller or to conduct group
operation in different refrigerant systems, the control line for transmission is
required between the outdoor units.
Connect this control line between the terminal blocks for centralized control.
(2-wire line with no polarity)
When conducting group operation in different refrigerant systems without con-
necting to the upper class controller, replace the insertion of the short circuit
connector from CN41 of one outdoor unit to CN40.
9 Group is set by operating the remote controller.
9.2. Control box and connecting position of
wiring
1. Connect the indoor unit transmission line to transmission terminal block (TB3),
or connect the wiring between outdoor units or the wiring with the central con-
trol system to the central control terminal block (TB7).
Example of a group operation system with multiple outdoor units (Shielding wires and address setting are
necessary.)
<Examples of Transmission Cable Wiring>
[Fig. 9.3.1] M-NET Remote Controller (P.4)
[Fig. 9.3.2] MA Remote Controller (P.4)
A Group 1 B Group 3
( ) Address
10
B Piping
D Heat insulation material A
C Group 5
Note:
• When using polyethylene cover as covering material, asphalt roofing shall
not be required.
• No heat insulation must be provided for electric wires.
[Fig. 8.4.2] (P.4)
A Liquid pipe B Gas pipe
D Finishing tape E Insulater
[Fig. 8.4.3] (P.4)
Penetrations
[Fig. 8.4.4] (P.4)
<A> Inner wall (concealed)
<C> Outer wall (exposed)
<E> Roof pipe shaft
<F> Penetrating portion on fire limit and boundary wall
A Sleeve
C Lagging
E Band
G Sleeve with edge
I Mortar or other incombustible caulking
J Incombustible heat insulation material
When filling a gap with mortar, cover the penetration part with steel plate so that
the insulation material will not be caved in. For this part, use incombustible materi-
als for both insulation and covering. (Vinyl covering should not be used.)
When using shielded wiring, connect shield ground of the indoor unit transmis-
sion line to the earth screw (
outdoor units and the central control system transmission line to the shield (S)
terminal of the central control terminal block (TB7) shield (S) terminal. In addi-
tion, in the case of outdoor units whose power supply connector CN41 has
been replaced by CN40, the shield terminal (S) of terminal block (TB7) of the
central control system should also be connected to the ground (
[Fig. 9.2.1] (P.4)
A Power source
2. Conduit mounting plates (ø27) are being provided. Pass the power supply and
transmission wires through the appropriate knock-out holes, then remove the
knock-out piece from the bottom of the terminal box and connect the wires.
3. Fix power source wiring to terminal box by using buffer bushing for tensile
force (PG connection or the like).

9.3. Wiring transmission cables

1 Types of control cables
1. Wiring transmission cables
• Types of transmission cables: Shielding wire CVVS or CPEVS
• Cable diameter: More than 1.25 mm
• Maximum wiring length: Within 200 m
2. Remote control cables
Kind of remote control cable
Cable diameter
Remarks
2 Wiring examples
• Controller name, symbol and allowable number of controllers.
Name Symbol
Outdoor unit controller
BC Controller
Indoor Unit Controller
Remote Controller
D Shielded Wire E Sub Remote Controller
C Electric wire
<B> Outer wall
<D> Floor (waterproofing)
B Heat insulating material
D Caulking material
F Waterproofing laye
H Lagging material
) and connect shield ground of the line between
B Transmission line
2
2-core cable (unshielded)
2
0.3 to 1.25 mm
When 10 m is exceeded, use cable with the
same specifications as (1) Transmission line
wiring
Allowable number of controllers
OC
BC One controller for one OC
IC One to sixteen controllers for one OC
RC Maximum of two per group
).