The internal oven set point temperature of the the oven-controlled crystal oscillator OCXO OH100-61003CF-020.0M (DigiKey Part# CW815-ND) from Connor Winfield is nominally 92°C. Each OCXO gets individually set to a temperature that matches the crystal unit’s turn-over point, and that turn-over point does vary from crystal to crystal. Some ovens are set hotter than others for that reason.
The principle of operation says that oven temperature set point should be a minimum of 7 degree C (up to 15 degree C) above the operating temperature at the upper range specified for the OCXO. Then it will require the ambient temperature inside the OCXO enclosure to remain at or below 85C during operation with some minimum tolerance designed in, to ensure that the oven circuit inside the OCXO does not completely turn off and lose control of the temperature at the crystal level.
If, however, the oven gets turned off due to the internal ambient temperature inside the OCXO enclosure exceeding the oven set temperature as was programmed during manufacturing, the result will be that the oscillator will continue to operate but follow the natural frequency vs temp response curve of the crystal itself. The likely scenario in this case is that the output frequency of the OCXO will increase relative to the SC cut crystal’s frequency response curve as it sits inside the oven enclosure/package. The temperature of the OCXO metal case itself does not necessarily coincide with the internal ambient within the enclosure due to thermal gradients that may vary as well as time lags for thermal transfer to occur.