8
1.4 Electrical
Connections
1.4.1
Important E.M.C. Considerations
Use a dedicated, earthed metal conduit for both the control
signal cable and the security circuit cables along their entire
length - they may share the same conduit where practicable.
The earth must be made by "metal-to-metal" contact and
should be a good RF (Radio Frequency) earth.
The control and security circuit connections should be run in
screened cable with the screen grounded at the VAPANET
end (onto the electrical section back panel). The screen
should be maintained as close as possible to the cable ends
and any tail between the screen and the earth point must be
kept short (50 mm maximum).
Control Cable / Security Circuit
Conduit Entry Arrangement
Control Cable / Security Circuit
Screening Arrangement
Tail to be kept short
(less than 50mm)
Cables to control terminals
Screen left intact
Outer insulation
Earthed back panel
Important Power Connection Information
Vapac 24V and 9 V secondary Transformer Primary supply connections:
Vapac units are wired to allow connection to alternative site Voltages.
Make the following simple checks before connecting the power supply:-
Move the RED connection on the VAPANET transformer primary winding circuit to the
position marked with the supply Voltage that is to be connected between VAPANET
power terminals A1 and A2.
The transformer primary circuit terminal positions are clearly marked:- 200V, 230V,
380, 415 & 440V.
If the actual (measured) site voltage is 400v the preferred
tapping is 380V.
The transformer is fitted below the Drain tray, and is accessible by
removing two screws and the cover, which should be slid it towards you.
Note:
24 V a.c. Control circuit
-
9 V a.c. PCB Circuit
-
Transformer Primary Circuit -
230V ac Pump Supply.
-
6.3 A 20 mm (T – Time Lag) fuse (Pt.No. 1080093)
mounted on VAPANET
Echelon PCB (Pt.No.1150630).
2 A 20 mm (F - Quick blow) fuse (Pt No. 1080099) mounted on the VAPANET
Echelon PCB (Pt, No. 1150630).
Two fuses protect the control circuit on Single cylinder units F1 2.0A (slow
blow) (Pt. No. 1080095) mounted in fuse-terminal holder protects Primary
transformer and RDU unit if fitted. F2 500 mA 20 mm (F - Quick blow) fuse (Pt
No. 1080054) mounted in fuse-terminal holder protects Transformer Primary
and Pump or both pumps if two pumps are fitted.
The pump or pumps on twin cylinder units are fed from the main transformer
via a 230 volt auto winding. The pumps are protected by fuse F1 and F2 above
feeding the transformer primary.
All metal surfaces which come
into contact with each other,
must be free of paint, grease,
dirt, etc., thereby ensuring a
good low impedance R.F.
(Radio Frequency) path to
ground.
Electrical section metalwork
Metal conduit
