The basic journal entry to record the sale of property, plant & equipment for cash is as follows:
Dr: Cash - to record proceeds received
Dr: Accumulated Depreciation - to remove depreciation accumulated to date
Cr: Equipment - to remove the equipment at cost
Dr/Cr: Loss/Gain on disposal - to record a loss/gain for the difference between the net book value of the equipment at the disposal date and the proceeds received
To determine the amount of depreciation accumulated to date, we must first determine the annual depreciation expense. Using the straight-line method, the computation is as follows:
(Cost - Salvage value) / Estimated use life in years.
Thus, the annual depreciation expense is: ($24,000 - $4,000) / 5 = $20,000 / 5 = $4,000.
In this case, because the sale was during the fiscal year at 9/30/2014 and depreciation was only recorded through 12/31/2013, we must first bring the depreciation up to date by increasing accumulated depreciation and recording the depreciation expense from 12/31/2013 to 9/30/2014, or 3/4 of a year. That amount would be the annual depreciation expense * 3/4, or $4,000 * 3/4 = $3,000. That entry would be:
9/30/2014
Dr: Depreciation expense $3,000
Cr: Accumulated depreciation $3,000
After that entry, the amount of accumulated depreciation at the sale date would be $4,000 for 2012 and $4,000 for 2013 and $3,000 for 3/4 of 2014, or $$11,000. Now we can complete the entry for the sale as follows:
9/30/214
Dr: Cash $17,000
Dr: Accumulated depreciation $11,000
Cr: Equipment $24,000
Cr: Gain on sale of equipment $4,000 (($24,000 - $11,000) - $17,000)
Hopefully that helps.