Auxilliary Contacts Found On The Main Board - Carrier 40MBAB Series Service Manual

40MBAB: Service Manual

AUXILLIARY CONTACTS FOUND ON THE MAIN BOARD

Work Terminal Port CN23 - Normally Open Dry Contact (Output)
• The WORK terminal port is linked to the unit's indoor blower
• When the indoor blower is off, the contact is open
• When the indoor blower is running, the contact is closed
• There is no voltage from CN23, power is provided from the external control system and not from the unit.
• The contacts are rated at 250VAC and 10 AMP maximum
• If an active 24V signal output is required, G and C ports (thermostat connections) may be used instead.
ALARM Terminal Port CN33 - Normally Open DRY CONTACT (OUTPUT):
• Allows the terminal port to connect to an external ALARM interface or annunciator
• There is no voltage from CN33, power is provided from the ALARM system and not from the unit.
• The contacts are rated at 250VAC and 10 AMP maximum
• When the unit experiences a problem, the contact closes, and the ALARM is triggered.
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
Fig. 1 — Auxiliary Contacts
Fig. 2 — Auxiliary Contacts
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