Overnight ratings in 10 major Nielsen markets indicate that the season premiere of "Dynasty" on Wednesday night scored enormous ratings for ABC. According to the figures released yesterday, 33.4 percent of all TV sets and 49 percent of the TV sets in use at the time were tuned in to see who survived the Moldavian massacre, compared with a 12.3/18 for NBC's "Hell Town" and a 9.2/13 for CBS' combination of "Charlie & Company" and "George Burns Comedy Week."

In Washington, "Dynasty" attracted an even larger portion of the audience, earning a 36.5 rating and a 51 share.

From 10 to 11 p.m., the season premiere of "Hotel" managed to hold onto the lead provided by "Dynasty," garnering a 22.6/36 in the 10-market averages, compared with a 13.9/23 for "St. Elsewhere" on NBC and an 11.7/19 for "The Equalizer" on CBS. "The Equalizer's" ratings were somewhat higher in Washington (13.3/21) although it still lagged behind "Hotel's" 22.3/36 and "St. Elsewhere's" 13.9/22.

ABC's first entry for the night, the debut of "The Insiders" at 8 p.m., did not win its time period in the 10 markets, averaging a 16.6/26, while NBC's "Highway to Heaven" did an 18.7/30, and CBS' "Stir Crazy" trailed with an 8.2/13. In Washington "The Insiders" did lead its time period with a 16.2/25, compared with a 15.1/24 for "Highway to Heaven" and a 12.5/19 for "Stir Crazy." Although the 10-city overnights give an indication of ratings performance, they do not include the rural markets reflected in national ratings, which are not yet tabulated.