Spectrex 20/20SH - Hydrogen Flame Detector - Manual (Page 36)

Spectrex Inc. - SharpEye TM Hydrogen (SH) Flame Detector Manual – TM 784600, Rev. A, May 2005
28
6.7 Terminal wiring (See Fig. No.10 and No.11.)
The detector contains a Terminal Board consisting of two (2) terminal blocks. The
left terminal block is labeled 1 to 7, the right terminal block is labeled 8 to 14.
The following describes the function of each electrical terminal of the
detector:
• Power Supply (Terminal Numbers 1, 2):
Input power -Terminal No. 1.
RETURN - Terminal No. 2.
• Manual Bit Activation (Terminal No. 3):
Terminal No. 3 is used for the Manual BIT activation. The manual BIT is
initiated by a momentary connection of Terminal No. 3 to the power supply
Return line.
Fault Relay (Terminal Numbers 4, 5):
The Fault output is N.O. SPST relay at Terminals No. 4 and 5. The contacts
are normally energized closed when the detector is in its normal operational
condition.
• Alarm Relay (Terminal Numbers 6, 7, 8):
The Alarm output is a change over contact relay (SPDT).
Terminal No. 6 is the N.O. relay contact.
Terminal No. 7 is the COMMON relay contact.
Terminal No. 8 is the N.C. relay contact.
• Accessory Relay (Terminal Numbers 9, 10):
The Accessory output is N.O. SPST relay at Terminals No. 9 and 10.
The Accessory relay may act in parallel with the ALARM relay to activate
another external device or it may provide a warning signal, depending on the
Function setup 4.3.1
Note
To protect the dry contacts from voltage surges when connected to reactive
loads (electric motors, sirens, etc.), connect an appropriate varistor over these
contacts.