Watlow series l rev g - 02-12-08.pdf - Manual (Page 22)

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Wa t l o w S e r i e s N 7
SSR Specification
Contact type: normally open
Maximum operating current: 0.4 A
Maximum operating voltage: 250VÅ (ac)
Pilot duty: 100 VA
No Arc Specification
Contact type: normally open
Maximum operating current: 8 A
Maximum operating voltage: 250VÅ (ac)
Note: These specifications are subject to change without
prior notice.
High-Voltage Modules Ordering Information
• A007-2660-0000 - 2 solid-state relays (0.4 A)
• A007-2660-0001 - 2 solid-state relays (0.4 A) and
4 mechanical relays (8 A)
• A007-2660-0002 - 6 solid-state relays (0.4 A)
• A007-2660-0003 - 4 solid-state relays (0.4 A) and
2 mechanical relays (8 A)
• A007-2660-0004 - 2 solid-state relays (0.4 A) and
4 no-arc relays*
Customer-Supplied Connectors
Standard I/O 16-pin connector housing - Molex part no.
43025-1600
Optional I/O 14-pin connector housing - Molex part no.
43025-1400
Pins - Molex part no. 43030-0007
*No-Arc Relay Definition:
A thyristor carries the load current for a brief period before the
relay contacts close. The voltage across the relay contacts prior
to closing is only a volt or two (the voltage drops across the
thyristor). When the relay contacts close, the load current flows
through the relay contacts, and the thyristor turns off. When
it’s time to turn the load off, the thyristor is gated ON just prior
to the relay contacts opening. As the relay contacts begin to
separate and the line voltage crosses zero, the thyristor again
goes into conduction and extinguishes the arcing between the
relay contacts. This great reduction in contact arcing (mainly
on relay opening) minimizes contact erosion and extends the
switch life of the relay.