IM-P403-89
EMM Issue 8
32
90 91 92 93 94 95 96 97 98
Bac
k
Fr
ont
76 77 78
73 74 75
70 71 72
50 51 52 53
56 57 58 59
60 61 62
Note:
Do not connect terminals 53, 54, 59, 60 or 78 to any other earth.
Ensure that resistance from the probe body to the pipework / boiler shell is less than 1 ohm.
E = Functional earth. Connect these pins to earth local to the panel.
Fig. 24 Signal circuit (view from the top)
Bottom blowdown switch
(shown with valve closed)
screen
Connect to local
earth in the panel
Connect
to local
earth in
the panel
Screen
Screen
Drive
Drive
sense
Com
sense
Com
Drive
Sense
Com
CP30 and CP32
conductivity probe
CP10 conductivity
probe
Blue (internally connected to probe body)
Red
Pt100
W
hi
te
Re
d
R
ed
or R
ed
trac
er
0 / 4 - 20 mA
output
54 55
Screen
See RS485 / Modbus wiring notes
SCN
E
5.4 Signal wiring notes
See Section 10, Technical Information, for terminal and cable specification.
An earth current loop is created if a wire or screen is connected between two earth points
that are at different potential (voltage). If the wiring diagram is followed correctly, the screen
will only be connected to the earth at one end.
The earth terminal is a functional earth rather than a protective earth.
A protective earth provides protection from electric shock under a single fault condition. A
functional earth is used in order for the product to operate. In this application, the functional
earth is used as a sink or drain for any electrical interference. The earth terminal must be
connected to a local earth in order to conform to the EMC directive.
5.5 Probe wiring
The maximum cable length for all probes is 100 m (9990 and 999.0 ranges), 10 m (9.990
range) or 30 m (99.90 range). All cables must be of the same gauge.
Содержание BC3250
Страница 76: ...IM P403 89 EMM Issue 8 76...