The Electricity Supply Rules made under Section 15 of the Electricity (Inspection) Act Chapter 54:72 provides for variation of six percent above or below the declared voltages.

Electrical equipment must be used by Consumers in such a manner as not to cause unusual voltage fluctuation or other disturbances to the Commission's system. The Commission will require Consumers at their own expense to install suitable apparatus to limit such voltage fluctuations and disturbances. The Commission reserves the right to take whatever action it considers necessary to correct or prevent such disturbances from unduly affecting the quality of supply to other Consumers.

See T&TEC Act 42 of 1945: Supply of Electrical Energy

Trinidad and Tobago Electricity Commission Act
Chapter 54:70
Act 42 of 1945

Nature and Mode of Supply

40. Electrical energy shall be supplied by means of the alternating system or the direct current system, for arc or incandescent lighting, or such other system as shall be approved by the President; and subject to such Regulations and conditions for securing the safety of the public and for ensuring a proper supply of energy as the President may from time to time impose.