Categories
HVAC Informational

Carrier Infinity Touch: Thermostat: Version Comparison

I recently started my search for a smart thermostat so that I can be lazy and change my thermostat from bed and to save money on my electric bill. I started digging to learn about my HVAC unit and I own a Carrier system.

From doing my homework (Web Searching), it appears that Carrier systems are quite good and can be do advanced things like zoning and coordinating varying numbers of different units: A/C, Heaters, Heat Pumps, Humidifiers, Heat Exchanger/Recovery Units, etc.

—-> Skip to the Comparison <---

Carrier Infinity systems do this by connecting all the controllers on a communication bus so all the units can communicate and share information. Carrier systems use 4 wires:A, B, C & D. A & B are the Serial Communication bus and C & D are the power wires. Sounds Great, right?!?

The flip side is this communication scheme makes these systems incompatible with just about EVERY smart thermostat out there. You can switch the unit to traditional thermostat wiring, but you lose things like variable fan control and other advance feature the carrier system can perform. No Nest, No Ecobee, No Honeywell or other smart thermostat.

Carrier (Also Bryant?) offers their own Infinity system capable touch screen, smart thermostat, but that sucker is expensive. So like any penny pincher, I started looking for a used one.

I found several model numbers out there: systxccitc01-b, systxccitc01-a, systxccitw01-a, systxccitw01-b, systxccitw01-a, systxccitn01-a, systxccitn01-a. Additionally, I found modules (remember the expand-ability I mentioned above?): systxccnim01, systxccrct01, systxccrwf01, systxcc4zc01, systxccsam01, systxxxgwro1. That’s quite a bit of different stuff.

(Using lowercase model numbers because the number look weird next to it. i.e. SYSTXCCITW01)

This post is to try to de-mystify these different models and units.

Thermostat Variants

  • systxccitc01 VS systxccitw01 VS systxccitn01
  • systxccitc01
    • Wifi capable
    • Intended to join your in-home wifi
    • Alternatively, connect to a special infinity access point (AP): systxxxgwro1.
  • systxccitw01
    • Wifi capable
    • Intended only to connect to a special infinity AP: systxxxgwro1.
    • Thermostat was bundled with the AP when new.
  • systxccitn01
    • Non-Wifi Version of the Smart Thermostat

Version A vs Version B

It appears that there is actually very little difference between version A and B of the systxccitc01, systxccitw01 and systxccitn01. Main difference seems to be:

  • Version B
    • Added occupancy sensing to change climate settings when you are home
      • This may not work well if you have pets

I merged the information from Carrier website about the systxccitc01-a and the systxccitc01-b into one graphic to elucidate the differences.

Click the thumbnail below:

SYSTXCCITC01-A Vs SYSTXCCITC01-B

Module Descriptions

The follow is my understanding of the various modules after a cursory examination of the various manuals. There may be some version numbers that I missed or compatibility between versions that I missed. Please refer to the manuals for each item to get more details.

  • systxxxgwro1 – Dedicated Wifi Access Point for Infinity equipment
    • Used to connect Infinity equipment on a separate wifi network .
    • Bridge the wifi to a network via ethernet
  • systxccsam01 (SAM) – System Access Module
    • Allow the Infinity system to interact with a home automation system via RS-232.
    • Allows remote access to an Infinity system via the Skytel Network (Paging System) in-lieu of a wifi capable thermostat.
  • systxccrct01 (CAT-5-B-SAM) – Ethernet Remote Access Module
    • Connects an Infinity system to network via ethernet for remote Access in-lieu of a wifi thermostat.
    • Can be used in-lieu of a smart thermostat to allow a user to change climate settings remotely.
    • Allow the Infinity system to interact with a home automation system via RS-232
  • systxccrwf01 (WIFI-B-SAM) – Wifi Remote Access Module
    • Connects an Infinity system to a network via wifi for remote access in-lieu of a wifi thermostat.
    • Allow the Infinity system to interact with a home automation system via RS-232
  • systxcc4zc01 (DCM) – Damper Control Module
    • This model number is to control 4 zones
      • (Does this mean 4 individual dampers? I am unsure)
    • This controls vent dampers for zoning a house and interfaces with the infinity system to receive and act on commands.
  • systxccnim01 (NIM) – Network Interface ModuleExcerpt from the manual:
    • The Network Interface Module (NIM) is used to interface the following devices to the Infinity ABCD bus so they can be controlled by the Infinity System. The following devices do not have communication ability and the NIM is required to control:
      • A Heat Recovery Ventilator / Energy Recovery Ventilator (HRV/ERV) (when zoning is not applied).
      • A non-communicating single-speed heat pump with Infinity furnace (dual fuel application only).
      • A non-communicating two-speed outdoor unit (R-22 Series-A unit)

I hope you found this helpful and enlightening.

Categories
Machine Shop Math

Angle of Engagement

The angle of engagement of a milling tool is not often thought about directly, but usually indirectly when considering the behavior of a tool when entering a corner (Chatter!! or Breakage!).

Some sites show how to calculate the Angle of Engagement (We Will TOO!), but mainly you get generic graphical representations that look like this:

Figure 1: Oh No! The Tool is in a Corner! Avoid This!

I personally find it frustrating when I’m interested in a deep dive in machining theory or would like to decide how deep to go. When faced with the above, theres no where to go because you’re in the shallow end of the information pool. So all you can do is machine like Rock Chipper.

Figure 2: Rock Chipper Says “Corners! Bad!”

We’re gonna try to be more useful than that.

Skip Ahead to the Answer:

—-> Skip to the Answer <---

When a tool manufacturer provides you with cutting data, the angle of engagement is fully defined with the manufacturer provided parameters and can be a useful tool to understand tool load.

Figure 2: Basic Tool Parameters

Modern “advanced” CAM roughing cycles are more in-tune with tool engagement and work to improve corner machining by preventing tool load spikes by doing things like maintaining a constant engagement angle, reducing step over and feed rate reductions.

Traditional tool paths calculations are based on a constant step over provided by the the programer which leads to load spikes as the internal radii being machined approaches the size of the tool. (CNC operators usually have to baby the machining and maybe wear earplugs)

The following diagram hopefully helps visualize the angle of engagement in several scenarios: .75″ Diameter, 6% step over

Figure 3: Scroll image to compare corner conditions

How do we compute the angle of engagement if we want to??!?


—-> Skip to the Answer Answer <---

We’ll start with defining our primary variables.

\[\] \begin{aligned} \Theta_{ae} = \text{Angle of Engagement} \end{aligned} \[R_T = \text{Radius of Tool}\] $$SO = \text{Step Over}$$
Figure 3:

Next we’ll breakdown our cutting operation into triangles. The goal is to produce Right Triangles (has a 90° Corner).

Figure 4: Boring Diagram

We have created a few more pieces so we will define any secondary variables to aid us in calculation and start creating our important relationships.

Secondary Variables:

\[R_C = \text{Left over portion of Line}\]

Our main interest is \(\Theta_{ae}\), so let us define it. Using our good ol’ friend and mnemonic SOH-CAH-TOA, \[\cos(\Theta_{ae}) = \frac{R_C}{R_T}\]

\(R_C\) is not currently known, but we can find it.

The Red line and the Blue line are the same length, \(R_T\).

So going from tool center to the tangent point of the cutter (Red Line), that means that the red line, \(R_T\), is made up of \(R_C\) and \(SO\). So, \[R_T = R_C + SO\]

Rearranging, we get \[R_C = R_T – SO\] We can, now, substitute the expression for \(R_C\) into the equation for \(\Theta_{ae}\). \[\cos(\Theta_{ae}) = \frac{R_T – SO}{R_T}\]

We can simplify the equation a bit by separating the common denominator. \[\cos(\Theta_{ae}) = \frac{R_T}{R_T} – \frac{SO}{R_T}\] which simplifys to \[\cos(\Theta_{ae}) = 1 – \frac{SO}{R_T}\]

To solve for \(\Theta_{ae}\) we take the inverse cosine/\(\arccos\)/\(\cos^{-1}\) of both sides, \[\cos^{-1}(\cos(\Theta_{ae})) = \cos^{-1}(1 – \frac{SO}{R_T})\]

Giving us our final equation for \(\Theta_{ae}\), \[\boxed{\Theta_{ae} = \cos^{-1}(1 – \frac{SO}{R_T})}\]

In case you skipped here: \[\Theta_{ae} = \text{Angle of Engagement}\] \[R_T = \text{Tool Radius}\] \[SO = \text{Step Over}\]

If you prefer to keep everything as a percentage of step over. We’ll make an additional relationship: \[SO = \frac{SO_{\%}}{100} * 2R_T\]

YouTube Tutorial:

Link to PDF of work from the video tutorial:

Angle of Engagement: Derivation and ExamplesDownload

My next post will likely be an online calculator to compute the Angle of Engagement.

What is it good for? Where do we go from here? Directly, I haven't found the angle of engagement to be that useful by itself, but it is necessary intermediate if you want to calculate the force on the tool or develop other cutting relationships.

This whole site started because a coworker asked me for a calculator to help him determine the step over necessary to maintain a constant angle of engagement for a specified corner radius. I couldn't find it online, so I derived it myself and I felt the need to put it "Out There". The math is pretty hairy and non-linear. I will show the mathematics and probably make an calculator in a future post.

Categories
Informational

The 1st Pass

Hello and Welcome to The Chip Hopper.

I expect the 1st pass to be pretty rough, but if we’re careful we’ll make some chips.

The hope for The Chip Hopper is to catch bits of what I learn as a Production Engineer in a repair facility. I hope to chronicle projects, code, tools, calculator and maybe sell things.

My skills are broad; CNC machine troubleshooting and maintenance, CAM Programming, Job setups, Excel Spreadsheet, VBA programming, CNC Macro development, Post Processor Editing etc… The usual “Jack of All Trades, Master of None” or Renaissance Man.

You can find out more about me when you visit “Dive into The Chip Hopper”.