You can remind the other party in writing to fulfill the acceptance obligation, and inform the delay acceptance of the legal responsibility and consequences. If the other party has been delayed acceptance, and the actual use of the equipment, the equipment can be considered to have passed the acceptance, the other party should pay the contractual payment.
It is recommended that in the future in the contract, "Party A late acceptance or the actual use of the equipment without acceptance, the equipment is considered to have passed the acceptance test".