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TC903-4FMSA FCU Room Thermostat

Wyman_Yeung
Crewman Crewman
Crewman
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6
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TC903-4FMSA FCU Room Thermostat

 

We have a project using TC903-4FMSA and will using AO to control the FCU fan speed.

But the customer require TC903 thermostat to repeat the Fan status.

Can we use the DO point (dry contact) to represent the Fan running status?

What is the DO point used for?

Please refer to attached wiring diagram.

 

 

Thx for advise?

 

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6 Replies 6
Gary
Commander Commander
Commander
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504

Re: TC903-4FMSA FCU Room Thermostat

Hello Wyman,

 

Re: Please refer to attached wiring diagram.

I do not see any attachments?

 

 

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Wyman_Yeung
Crewman Crewman
Crewman
0 Likes
2
492

Re: TC903-4FMSA FCU Room Thermostat

We have a project using TC903-4FMSA and will using AO to control the FCU fan speed.

But the customer require TC903 thermostat to repeat the Fan status.

Can we use the DO point (dry contact) to represent the Fan running status?

What is the DO point used for?

Please refer to attached wiring diagram.

 

 

TC903-4FMSA wiring diagram.png

Tags (1)
CraigEl
Administrator Administrator
Administrator
0 Likes
1
478

Re: TC903-4FMSA FCU Room Thermostat

Hi Wyman

 

I suspect that the ECM fan requires some sort of PWM control and that is why the DO is required.

Wyman_Yeung
Crewman Crewman
Crewman
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461

Re: TC903-4FMSA FCU Room Thermostat

Well noted and many thx.

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Emmerich
Cadet
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0
307

Re: TC903-4FMSA FCU Room Thermostat

Thanks for sharing i was curious to know about it and this was true and solved my issue thanks for your support.

Myloweslife

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PetZeri
Cadet
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0
165

Re: TC903-4FMSA FCU Room Thermostat

The advanced indoor regulator are only for room temperature control in 2-lines and 4-pipes FCU cooling frameworks with 3-speed fan and a couple of water valves. Highlights: - Designed for control a 3-speed fan and a couple of water valves with fan speed auto or manual change selectable.

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