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Phason 

 

MTC-3C installation guide 

10340009  

MTC-3C installation guide 

The Modulating Temperature Control (MTC-3C) allows you to automatically control ventilation fans according to the ambient 
temperature.  

When the temperature is at or below the temperature set point, the MTC-3C operates the fans at the idle speed setting. When 
the temperature exceeds the temperature set point, the MTC-3C increases the speed. When the temperature increases 6°F 
above the temperature set point, the MTC-3C increases the speed to maximum. 

 

Features 

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One variable speed output 

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Adjustable 40-90°F temperature set point 

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6°F temperature differential 

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Automatic and manual modes 

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Adjustable idle speed for automatic mode 

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One-foot temperature probe, extendable to 500 feet 

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Overload protection fuse 

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Rugged enclosure (corrosion resistant, water resistant, 
and fire retardant) 

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CSA approval 

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Two-year limited warranty 

 

Electrical ratings

 

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120/230 VAC, 60 Hz 

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10 A at 120/230 VAC, general-purpose (resistive) 

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8.5 A model also available 

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7 FLA at 120/230 VAC, PSC motor 

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1/2 HP at 120 VAC, 1 HP at 230 VAC, PSC motor 

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Fuse: 15 A, 250 VAC ABC-type ceramic 

 

 

 
 
 
 
 
 

 

 

The MTC-3C is designed for high current and is too strong for small motors. The MTC-3C might not operate 
properly when running fan motors with a very inductive power factor and that draw less than 0.5 A. To test 
for this problem, connect the control to the motor and adjust the control from minimum to maximum. If the 
motor jerks or locks during any part of the range of operation, the current draw is too low.  

Adding more motors in parallel to increase the current draw, or wiring and using the motor for 120 V 
operation can solve the problem. If this is not a viable solution, an 8.5 A version (MTC-3C-8.5) is available 
from your dealer. 

 
 

Installing the MTC-3C 

 

The MTC-3C must be installed by a qualified electrician.  

Before installing or servicing the MTC-3C, switch OFF the power supply at the source.  

Install the MTC-3C and all equipment connected to it according to local electrical codes. 

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