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OVERLOAD KITS FOR MCU / MCU+ 55000408 to 410, 446 and 449
These kits are for use on all single phase 550 series condensing units to provide a mains voltage alarm signal at terminal
5 when the compressor trips.
They may also be used as a spares replacement.
MCU,
MCU+
R22
NOMINAL
SETTING (A)
R407C
NOMINAL
SETTING (A)
QTY
DESCRIPTION
KIT No.
KIT No.
15
55000408
5.0
55000409
6.2
1
Overload
20
55000409
6.6
55000410
8.1
1
Pink Wire (98 - 5 or 2)
30
55000409
7.4
55000410
9.2
1
Violet Wire (96 - A1)
40
55000410
8.8
55000446
12.4
1
Black Wire (95 - 97)
50
55000446
11.0
55000446
11.0
2
Cable Tie
60
55000446
12.5
55000446
12.5
55000446
14.0
55000446
15.0
80
55000446
14.0
55000449
15.0
90
55000449
20.0
55000449
20.0
ISOLATE THE UNIT ELECTRICALLY PRIOR TO INSTALLATION OF THE KIT/SPARE
SPARES REPLACEMENT:-
The overload is a direct spare replacement. Set the overload to the original Amps setting and transfer all wires one at a
time: maintain the same relative positions of wires and ensure that a black wire is connected between terminals 95 and
97, using the supplied black wire if necessary. Discard other wires supplied in the kit. Check correct compressor rotation
on 3Ø units.
KIT FITTING
1
Remove the front access panel (three screws) to reveal the electrics box.
2
Set the overload as close as possible to the nominal figures in the above table.
3
Locate the contactor and transfer the wires from terminals 2, 4 and 6 to the corresponding terminals on the overload,
one terminal at a time.
4
Connect the pink wire supplied in the kit between terminal 5 on the terminal rail and overload terminal 98.
5
Remove the violet wire from contactor terminal A1 and reroute to overload terminal 95, also linking the black wire from
terminal 97 to terminal 95.
6
Secure the overload to the contactor by inserting the metal pins into vacant contactor terminals 2/4/6 and tightening
the screws securely.
7
Connect the violet link wire from the kit between contactor terminal A1 and overload terminal 96.
8
Tidy wires using the cable ties supplied.
9
Press the large central red button to ensure that the overload is reset.
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Heronhill - for all your IMI requirements
Tel: 01823 665660
www.heronhill.co.uk
Fax: 01823 665807