Window Channel Balance Options

A handy person from Orange Co. CA. 92688 says:
Hi, I want to replace channel balances in two windows, one of the window balances are marked as follows: 33 4 GO and 33 2 FO they measure 34" long and are 9/16" wide with a hemmed edge while the window measures 34.75" long x 44.75" wide. The second window measures 33" wide x 29" long and the balances are 28" long x 9/16 wide with hemmed edge. They however, have no markings of any kind. both windows use the 380 series. Is it possible to talk with someone? I want to order the parts a.s.a.p. Thanks. James
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Donna from SWISCO responded:
Hi James,
You have a good start with the Series 380 identified and the balance lengths. Next, remove each sash (the ones you are replacing the balances) and place each sash on a scale one at a time. The weight of the window sash in pounds is needed to determine the proper stamp option.
The following are the weight ranges for each available option for the 28" and 34" Series 380 balances.

2710 will carry a window sash weight range of 5 through 9 pounds
2720 will carry 9 through 13 pounds
2730 will carry 13 through 19 pounds
2740 will carry 19 through 26 pounds

3310 will carry a window sash weight range of 8 through 13 pounds
3320 will carry 13 through 18 pounds
3330 will carry 18 through 23 pounds
3340 will carry 23 through 28 pounds
3350 will carry 28 through 32 pounds

This information is based on 2 balances per sash. Balances are designed assuming friction in the jamb weather-strip will carry a portion of the sash weight. Suggested sash weights are approximate.
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