Electrical Connections - Marstair IMPACT 20 Technical Manual

ELECTRICAL CONNECTIONS

1 Mains, control and interconnecting cables must be supplied and fitted by the installer.
2 Installer wiring must be carried out in accordance with IEE regulations and local codes. Refer to the
interconnecting wiring diagrams on pages 30 to 34.
3 Mains supply cables must be size compatible with the recommended fuse for a given system (see
pages 11 and 12).
4 An all pole isolator switch should be positioned within easy reach of the indoor unit.
5 The equipment must be earthed.
Cable clamps for use with stranded cables are supplied in units 15 - 90 and should be used to secure
6
all incoming/outgoing cables. Installers must supply a method of securing any solid sheathed cables.
ELECTROMECHANICAL SYSTEMS
Systems including an electromechanical unit require a supply to the condensing unit with connecting cables
run to the indoor unit
ELECTRONIC SYSTEMS (DCU+, DHPUE and MHPUE):
It is recommended that systems with electronic indoor AND electronic outdoor units have a supply taken to
the outdoor unit AND a separate supply taken to the indoor unit, which in many cases can be from a
domestic 13 Amp socket, (see fuse ratings on pages 11 and 12), otherwise run a supply to the outdoor unit
with connecting cables run to the indoor unit.
Communication between the indoor and outdoor unit is via a two wire (max. 0.75mm
connection (installer supplied), using cable type RS 485 or equivalent, (or two cores of 00526077, 4 core
cable, available from TEV Ltd).
The cable screen should be secured to ground (earth) at BOTH ends using the clamps provided. Do
not attempt to run the communication in the spare cores of any power carrying cable.
Whenever possible, the communication cable should be run separate from any mains cable.
DATA PLATES
Because of the ability to mix-match indoor and outdoor units, the data plate only gives information on
outdoor units. To obtain the system details, input power and currents from indoor and outdoor units should
be added together. Data plates show basic units with electric heater kit loads shown separately.
FIRE LINK
In order to automatically switch off the fan in the event of a fire, it is necessary to fit an external switch (240V,
3A, closed to run, volt free contact) in series with the small black wire connected to the bottom terminal of the
fuse. This switch should be operated by the building's fire alarm or BMS system.
EVACUATING
1. Connect a vacuum pump to the service ports on the outdoor unit valves and evacuate the
interconnecting pipework and indoor unit to 1000 microns (1 Torr) or better and allow to be held for a
minimum of 15 minutes.
2. If NO additional refrigerant charge is required: Replace the caps on the service ports, (tighten to a
torque of 25NM), and open the valves using a 4 or 5mm Allen key. On electronic units, REMOVE link
JP6 identified by a white label, (otherwise the unit will always run at full speed).
Tel: 01823 665660
Heronhill - for all your Marstair requirements
13/20
www.heronhill.co.uk
2
) non-polarised
53799173-05
Fax: 01823 665807