At 1520 GMT, the rand traded at 17.2525 against the dollar, 0.28% weaker than its previous close. The dollar was
0.27% firmer against a basket of major currencies.
The South African Reserve Bank (SARB) will announce its rate decision on Thursday, with 11 of the 20 economists polled by Reuters predicting a hike of 50 basis point (bps) to 7.50%. Eight projected an increase of 25 bps and one no change.
Most economists polled by Reuters see no further rate hikes after this week.
"The rand could gain somewhat on a 75bp increase in the repo rate instead of 50bp this week, although the ongoing loadshedding remains a substantial, overshadowing negative effect on the domestic currency," Investec analyst Annabel Bishop said.
Loadshedding, a term for scheduled power cuts, has become a daily occurrence in South Africa, crippling business activity and weakening investor confidence.
The government's benchmark 2030 bond was up on Tuesday, with the yield down 3.5 basis points to 9.745%.
On the Johannesburg Stock Exchange, the Top-40 index and the broader all-share index closed down about 0.1%.
(Reporting by Anait Miridzhanian and Nellie Peyton; Editing by Uttaresh.V and Mark Porter)
