Crj-700 captain reported an EICAS red and amber warning that resulted in an air return.

Attributes
ACN	1674822
Time
Date	201908
Local Time Of Day	1201-1800
Place
Locale Reference	CLT.Airport
State Reference	NC
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Regional Jet 700 ER/LR (CRJ700)
Operating Under FAR Part	Part 121
Flight Phase	Climb
Flight Plan	IFR
Component
Aircraft Component	Engine Air
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Instrument Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine
Events
Anomaly	Aircraft Equipment Problem Critical Deviation - Procedural MEL Deviation - Procedural Published Material / Policy

Narrative:

The left air conditioning pack was deferred. On climb out; passing through 4;000 ft.; we got an EICAS red warning message right bleed duct which changed to amber after about 10 seconds. We ran the QRH and returned to clt unpressurized. We contacted the company; cabin crew; and ATC.likely the increased demands on the remaining air conditioning pack with climb thrust.

Original NASA ASRS Text

Title: CRJ-700 Captain reported an EICAS red and amber warning that resulted in an air return.

Narrative: The left air conditioning pack was deferred. On climb out; passing through 4;000 ft.; we got an EICAS red warning message R BLEED DUCT which changed to amber after about 10 seconds. We ran the QRH and returned to CLT unpressurized. We contacted the company; cabin crew; and ATC.Likely the increased demands on the remaining air conditioning pack with climb thrust.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.