The Virginia State Corporation Commission asked Virginia Electric and Power Co. yesterday to explain the circumstances behind its decision to guarantee $1.4 million in bank loans to three real estate groups that have links to a member of the Vepco board of directors.

The loans, arranged last year, kept the three partnerships from bankruptcy at a time when they owed Vepco $1.2 million in upaid electricity bills. Although Vepco board member William T. Roos had sold his interest in one of the firms - Tidewater Management Co. - a year before joining Vepco's board, he would have had "contingent liability" for the firm's debts if it had gone bankrupt, according to a Vepco statement.

A representative of Consumer Congress, a Tidewater and Falls Church based utility critics' group, raised the issue of the loans during a Richmond hearing on Vepco's request for a rate increase.

"Vepco let these large users run up debts over $1 million, yet threatens to shut off senior citizens who owe less than $50," the group said in a statement. "This is another graphic example of Vepco mismanagement."

Vepco executive vice president William W. Berry said the utility backed the loans in order not to lose all chance of recovering the $1.2 million it was owed. Roos, he said, did not initiate the loan guarantee, did not take part in the discussions of it and did not vote on the matter.

Berry said three other Vepco board members also abstained from voting on the matter because of their directorships on the board of United Virginia Bank, which made the loans in question, along with First and Merchants National Bank. He identified them as K. A. Randall of New York, William F. Vosbeck of Alexandria and Roy R. Smith of Staunton.

The case centers on unpaid electricity bills from 1975 to 1977 at 12 apartment complexes with 3,000 residents, located in Charlottesville, Richmond, Virginia Beach and the Hampton peninsula. All are owned or managed by firms dominated by Marcus and Melvin Weinstein of Richmond: Weinstein Associates and Weinstein Management Co. of Richmond and Tidewater Management Co., of Hampton.

Berry said the apartment tenants had been paying their rent, which included utility bills. "The landlord wasn't meeting obligations, but if we have to terminate service for nonpayment, the people who suffer would be the tenants," he said. Vepco accepted promissory notes totaling $986,000 and secured by $1 million in Weinstein property in September, 1976, rather than cut off power, Berry said, but the bothers once again fell behind in their payments.

"It was a no-win situation. If we'd cut off the electricity everyone would have called us inhuman. If we'd foreclosed everyone would have lost a hell of a lot of money, including us," Berry said, since the value of the property put up as security had been overtaken by electricity bills accumulating at the rate of $200,000 a month.

In the end, Vepco endorsed a $1.2 million loan from the two banks to the Weinstein's, with which the brothers paid the electric bill. Vepco also guaranteed a future $210,000 loan from the banks to cover conversion of the apartments from master (central) metering to individual electric meters, and accepted a direct promissory note from the brothers for $440,000 to cover security deposits on the electric service. The Weinsteins put up four more parcels of property to secure the total.

All three notes come due July 31, "and there will obviously have to be some renegotiation if this thing is to be paid off," Berry said.

Roos, who sold his interest in Tidewater Management on Jan. 1, 1975, retains "contingent liability" on debts the firm contracted while he was a partner but has no liability on the current loans, Berry explained. Roos remains associated with the Weinsteins in three other housing development partnerships that are not involved in the Vepco case: Lakeshore Associates, Hampton Associates and Queens Terrace Associates, Berry said.

"This complicated agreement maintained the opportunity for full recovery of our money," Berry stressed. "The fact that it has third-or fourth-hand benefit to one of our directors seems to me of minimal importance considering the options that were available to us."