AN MLG COMMERCIAL FIXED WING ACFT EXPERIENCED LOSS OF CABIN PRESSURE AT FL290 CAUSED BY THE FO'S ERRONEOUS INPUT TO THE PRESSURIZATION PANEL.

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I WAS FLYING WITH A NEW FO ON HIS IOE FROM ORD-PIT. THE FO'S DUTIES ARE TO SET THE PRESSURIZATION PANEL BEFORE TKOF INCLUDING THE DEST ARPT'S LNDG ALT SO THAT THE AUTOMATIC MODE OF THE PRESSURIZATION WOULD WORK. PIT ALT IS 1204 FT. THE FO ACCOMPLISHED HIS PREFLT ITEMS; BUT WE WERE HURRIED DUE TO A LATE ARR ON THIS THROUGH-FLT. WE DEPARTED ORD UNEVENTFULLY AND LEVELED OFF AT FL290. AT 3000 FT AGL ON CLB; I COMPLETED THE AFTER TKOF CHKLIST; WHICH INCLUDES CHKING THE PACKS AND ENG BLEEDS. ADDITIONALLY; CLBING THROUGH FL180 I CHKED ACFT PRESSURIZATION AND ALL APPEARED NORMAL. APPROX 5 OR 10 MINS AFTER REACHING CRUISE ALT WE HEARD THE CABIN ALT WARNING HORN SOUNDING. INITIALLY; I THOUGHT IT WAS THE TKOF WARNING HORN SINCE IT SOUNDS THE SAME. WE SILENCED THE WARNING HORN; AND I NOTED THE CABIN ALT WAS CLBING ABOVE 10000 FT. I INSTRUCTED THE FO TO DON HIS OXYGEN MASK AND I DID THE SAME. THERE WERE NO WARNING LIGHTS TO INDICATE ANY PROBS WITH THE AUTOMATIC MODE OF THE PRESSURIZATION; BUT I ELECTED TO SWITCH TO THE STANDBY MODE. AS SOON AS STANDBY WAS SELECTED THE CABIN ALT BEGAN DSNDING AND RESPONDED NORMALLY. UPON EVALUATING WHAT HAD CAUSED THE PROB; I REALIZED THE FO HAD INCORRECTLY SET THE LNDG ALT IN THE AUTOMATIC SIDE OF THE PRESSURIZATION TO 12040 FT INSTEAD OF 1204 FT. THE FACT THAT THIS WAS ONLY THE FO'S SECOND DAY OF LINE OPS AND FIFTH LEG ON ACFT; IT WAS NIGHT; AND WE WERE VERY BUSY DUE TO A QUICK TURNAROUND; WE MISSET THE PRESSURIZATION UNIT WHICH CAUSED OUR PROB; AND FROM MY SEAT ON THE L SIDE WAS NOT ABLE TO CATCH THE MISSETTING.