The SW88 has been designed for direct current loads, particularly motors as used on electric vehicles such as industrial trucks. Developed for both interrupted and uninterrupted loads, the SW88 is suitable for switching Resistive, Capacitive and
Inductive loads.
• Interrupted current : opening and closing on load with frequent switching
(results in increased contact resistance).
• Uninterrupted current : no or infrequent load switching requirements
(maintains a lower contact resistance).
The SW88 features single pole double breaking main contacts with silver alloy tips, which are weld resistant, hard wearing and have excellent conductivity. The SW88 main contact circuit, designed for motor reversing, is such that it has a built in failsafe, so that if both coils are energised simultaneously the contact arrangement is open circuits. The SW88 has M8 stud main terminals and 6.3mm spade coil connections.
Mounted using supplied brackets, mounting can be horizontal or vertical, when vertical the M8 contact studs should point upwards. If the requirement is for downwards orientation we can adjust the contactor to compensate for this.

Thermal Current Rating ( I th)
Intermittent Current Rating:
30% Duty
40% Duty
50% Duty
60% Duty
70% Duty
Rated Fault Current Breaking Capacity ( I
(in accordance with UL583) cn) 5ms Time Constant:
SW88
SW88B
Maximum Recommended Contact Voltages (Ue):
SW88
SW88B
Typical Voltage Drop per pole across New Contacts at 100A:
Normally Open
Normally Closed
Mechanical M.T.B.F
Coil Voltage Available (Us) (Rectifier board required for A.C.)
Coil Power Dissipation:
Highly Intermittent Rated Types
Intermittently Rated types
Prolonged Rated Types
Continuously Rated Types
Maximum Pull-In Voltage (Coil at 20˚ C) Guideline:
Highly Intermittent Rated types (Max 25% Duty Cycle)
Intermittently Rated types (Max 70% Duty Cycle)
Prolonged Operation (Max 90% Duty Cycle)
Continuously Rated Types (100% Duty Cycle)
Drop-Out Voltage Range
Typical Pull-In Time
Typical Drop-Out Time (N/O Contacts to Open):
Without Suppression
With Diode Suppression
With Diode and Resistor (Subject to resistance value)
Main Contact Change over time (milliseconds)
Normally Closed to Normally Open
Normally Open to Normally Closed
Typical Contact Bounce Period
Operating Ambient Temperature
Guideline Contactor Weight:
SW88
Per Auxillary
With Blowouts
Auxiliary Thermal Current Rating
Auxiliary Contact Switching Capabilities (Resistive Load):
SW88A & SW88C
SW88A & SW88C
SW88A & SW88C
Copper busbar
Cable
100A
185A
160A
140A
130A
120A
800A at 48V*
600A at 80V*
48V D.C.
96V D.C.
40mV
50mV
>5 x 10 6
From 6 to 240V D.C.
20 – 30 Watts
15 – 20 Watts
13 – 15 Watts
7 – 13 Watts
60% Us
60% Us
60% Us
66% Us
10 – 25% Us
20ms
5ms
50ms
8 – 20ms
7ms
4ms
3ms
–40˚C to +60˚C
910 gms
+20 grams
+50 grams
5A
5A at 24V D.C.
2A at 48V D.C.
0.5A at 240V D.C.
80mm 2 [0.124inch
2 ]
Rated suitable for Application
NOTE: Performance data provided should be used as a guide only. Some de-rating or variation from figures may be necessary according to application.
Thermal current ratings stated are dependant upon the size of conductor being used.
* Normally Open contacts only - Normally Closed should be rated as per Interrupted Current, and are not designed to make and break load
900
800
700
600
500
400
300
200
100
0
100
200 300 400
Current (Amperes)
500 600
Interrupted Current and Uninterrupted Current
700
SW88A
SW88C
is a trademark of Curtis Instruments, Inc.
Specifications subject to change without notice ©2013 Curtis Instruments, Inc.
Manufactured in the UK by Albright International Ltd. and Distributed in the USA by Curtis Instruments, Inc.
Figures are for guideline purposes only
Auxiliary Contacts
Auxiliary Contacts – V3
Magnetic Blowouts
†
Magnetic Blowouts – High Powered †
Armature Cap
Mounting Brackets
Magnetic Latching † (Not fail safe)
Closed Contact Housing‡
Environmentally Protected IP66
EE Type (Steel Shroud)
○
X
X
○
●
○
○
○
○
○
Large Tips
Textured Tips
Silver Plating
○
○
X
AC Rectifier Board (Fitted)
Coil Suppression †
Flying Leads
Manual Override Operation
M4 Stud Terminals
M5 Terminal Board ○
○
○
X
○
○
○
Vacuum Impregnation
Key: Optional
○
Standard
●
Not Available X
† Connections become polarity sensitive
‡
Open Housing Available
A
C
B
B
M
L
T
F
800
50254AL REV A 9/13