The mods at English Usage are intent on undeleting bad answers, even though I've retracted them. In trying to prune, they give suspensions. What are the rules on that? It's literally only a handful of answers, and of course the accepted answers remain untouched.
Speaking as a moderator on another site, what probably happened was that you recently deleted a number of posts and that triggered an automatic flag. We see these as "possible vandalism: deletions (auto)" flags with a list of recently deleted posts.
If they reviewed the posts and found that they contained content worth saving, the moderators might have undeleted those posts and provided our standard warning about a potential rage-quit in action. That moderator message template reads like the following:
I'm writing in reference to your [site] account:
You have recently removed or defaced a lot of content from your posts. Please note that once you post a question or answer to this site, those posts become part of the collective efforts of others who have also contributed to that content. Posts that are potentially useful to others should not be removed except under extraordinary circumstances. Even if the post is no longer useful to the original author, that information is still beneficial to others who may run into similar problems in the future - this is the underlying philosophy of Stack Exchange.
Extensive deletions take a lot of effort to repair. I have placed your account on hold for 1 day while I reach out to you to avoid any further misunderstandings. Once this matter has been resolved, your reputation score will be restored and your account will resume as normal.
Please respond to this message. I sincerely hope this is just a misunderstanding, but if you feel you have an exceptional reason to remove this content then let me know. If you'd prefer, you can contact Stack Exchange directly through the 'contact us' link at the bottom of the site.
Regards, [site] Moderation Team
By default, the system triggers a one-day suspension to go along with this message. The purpose of that is to prevent any further deletions and give you a chance to respond. We quickly lift these suspensions if someone provides a good reason why this wasn't a rage-quit, a student trying to hide all their homework at the end of a term, or some other kind of vandalism.
If you respond to that message using your on-site account, and explain what's going on, the moderators will see that response and can lift your suspension. Additionally, as suggested in the message, you can use the "contact us" link at the bottom of every page on the site to get a hold of SE employees. They might not be able to respond as quickly as per-site moderators, due to having to develop for and oversee all of these sites.
Is deleting answers you feel are not good answers a suspension-worthy action?
Generally not. Sometimes an answer you gave wasn't that good in retrospect. It is fine to delete an answer if you think it should be deleted.
So what happened really? I guess it was something in the line of this: you deleted quite some answers. Your behavior triggered the rage quit warning in a moderator dashboard. The moderator suspended you to prevent more damage to the site.
If the moderator didn't immediately suspend you and just undeleted those answers, and you wanted to override that by deleting the posts again, that would definitely qualify as a reason to suspend.
What you should have done in such a case: ask on the site's meta what to do. Discuss what you want to do and wait on consensus. Or contact the team by using the Contact Us page.