NuAire LabGard NU-581-400E, Operation And Maintenance Manual

Page: 96 / 108

OM0303
Rev 5 July/2021
Page 96 of 108
9.0 Remote Contacts
The NU-581E has several contact closures for remote sensing of various functions.
9.1 Fan Relay
The fan relay contacts are dual normally open contact closure outputs which are activated whenever the blower is turned
on. Contact ratings are 250 VAC maximum at 2 Amps.
9.2 Alarm Relay
The alarm relay contacts are dual normally open contact closure outputs which are activated whenever an airflow alarm
condition occurs. An airflow alarm condition will occur if either airflow sensor detects 5 consecutive 2 second airflow
readings above or below the alarm limits. Contact ratings are 250 VAC maximum at 2 Amps.
9.3 AUX Relay
The AUX relay contacts are common, normally open and normally closed contact closure outputs which are activated
whenever the bower is turned on. However, the AUX relay does have some conditional logic programmed. The relay will
activate whenever the blower is turned on and stay on unless after 5 minutes there is a low exhaust alarm, then the relay
will deactivate. If exhaust is sufficient, the relay will stay active. If the blower is then turned off, the relay will stay active
for one minute then deactivate. The AUX relay may also be selected to operate the same as the fan relay. Reference the
AUX relay function in the option menu. Contact ratings are 250 VAC maximum at 2 Amps.
9.4 Remote Override
The remote override contacts (P-26 RMO) are (no power) shorting contacts only, which when closed, indicates to the
control system to shut down the cabinet. The blower would be turned off, an audible alarm would be turned on for several
seconds and the clock display will indicate "RM.OV".