Using pot equity to decide between raising or calling

[pergesu]

I was just reading an early part of SSH, and in the section on pot equity he says not to spend 1 bet to protect a pot equity of 0.5 bets. Later on he says if your pot equity is 1.7 bets then you should raise, because you have an edge and every bet that goes in is +EV for you. That all makes sense, easy stuff. Then in the wrap up he says that you use pot equity to determine whether to call or raise...that's where he lost me. Seemed like he said if you have less than 1 bet in pot equity you should fold, if you have more than 1 you should raise. So I guess the only time to call would be when you have exactly 1 bet of pot equity? Also I suppose times where you're close, like 0.8-0.9 and have implied odds. I'd like a better interpretation of this.