Fridgewatch 2100 Controller Mk4
Section 3
Publication 3-58
Issue 1.1 : 01/08
Page 39 of 152
To avoid problems of electrical interference, all low voltage wiring
(transducers, data communications and 24 V dc) must be adequately
separated from higher voltage ac wiring (110 V, 240 V, 415 V or higher).
A separation of 150 mm is desirable but not always achievable within
control panels. Low voltage and higher voltage cables should cross at
right-angles.
6.5.1.
Opto-Electronic Liquid Sensor Interface Unit
A specially designed interface unit converts the signal from the opto-
electronic liquid sensor, used for oil separator/reservoir low level, into
volt-free contacts for use on the 3MIO1 and 3MIO2 digital inputs.
If an oil level switch is fitted instead of an opto sensor, the opto sensor
interface is not used. Disconnect the opto sensor interface output wires
from the 3MIO1 card and wire the oil level switch (contacts open on fault)
in its place; refer to Fig 24.
6.5.2.
Connections to Economiser Solenoid Valves
Typical economiser arrangements, and wiring connections to the
economiser solenoid valves, are illustrated in Fig 12.
6.5.3.
Wiring Connections to Electronic Cards
In a multi-compressor application, wiring each compressor to a particular
input/output card determines the number of the compressors as
displayed on the front panel. Fig 4 shows the relative position of the
cards.
In the wiring connection illustrations the terminal numbers are prefixed
according to the position of the card in the Fridgewatch 2100 panel; refer
to Table 4.
6.5.4.
Jumper Connections on Electronic Cards
Once wiring connections have been made, the jumpers on the 3MIO1
and 3MIO2 input/output cards must be set as illustrated in Fig 23 and
Fig 25.
C
ARD
1
P
REFIX
F
IGURE
R
EF
C
ABLE
E
NTRY
R
EMARKS
3SCOP1
card No 1
1 = compressor 1
Fig 18
-
3SCOP1
card No 2
X = 2 for compressor 2
Fitted if FW2100 controls 2 compressors.
3SCOP1
card No 3
X = 3 for compressor 3
Fig 19
Bottom entry
to enclosure
Fitted if FW2100 controls 3 compressors.
3MIO1
1 = compressor 1
Fig 24
The card immediately adjacent to the mounting
board; refer to Fig 4. Analogue inputs for
pressure and/or temperature are made to this
card.
3MIO2
card No 1
X = 2 for compressor 2
Fitted if FW2100 controls 2 compressors.
Mounted on stand-offs above the 3MIO1 card.
3MIO2
card No 2
X = 3 for compressor 3
Fig 26
Side entry to
enclosure
Fitted if FW2100 controls 3 compressors.
Mounted on stand-offs above 3MIO2 card No 1.
1
It is important to note that these prefixes: 1, 2 or 3, are only included in the illustrations to distinguish between the different
cards and do not physically appear on the cards.
NOTE: when handling electronic cards, the precautions detailed in 2.1. Anti-Static Precautions must be taken.
Table 4 Wiring Connections to Electronic Cards
