SIEMENSPOL687.70/MCQClimatix 600 HVAC and Refrigeration Base Controller with Integrated LCD and Roll-and-Push HMI, 24 V AC/DC, 27 I/O, Ethernet, RS-485 Modbus, KNX, SD Card

Product Description

What this part is

The POL687.70/MCQ is a Climatix 600 base controller — the plant CPU, not an I/O expansion module. The .70 in the type number means the integrated HMI is fitted; POL687.00 is the same controller without a display. The /MCQ suffix is the OEM variant loaded for Daikin Applied / McQuay, which is why the unit itself is badged MicroTech III and MT3006 and carries a yellow U.C. (Unit Controller) tag.

I/O complement — the 27 points, itemised

8 universal I/Os, software-configurable as Ni1000, Pt1000, NTC 10k, NTC 100k, 0–2.5 kΩ, 0–5 V ratiometric, 0–10 V or 0/4–20 mA inputs, or as 0–10 V analogue outputs (X1–X4) and 0–10 V / 24 V DC 25 mA switched outputs (X5–X8)3 dedicated analogue inputs for NTC 10k and NTC 100k sensors2 digital inputs for potential-free contacts, counter capable to 100 Hz2 digital inputs 24 V AC/DC, galvanically separated2 digital inputs 115/230 V AC, galvanically separated8 relay outputs — 6 normally open plus 2 changeover — 24 to 230 V AC, max 3 A resistive / 2 A inductive at cosφ 0.62 triac outputs, 24 to 230 V AC, max 500 mA / min 30 mA

Why the mains-rated digital inputs and triacs matter

Most building controllers of this size are pure 24 V devices, which forces an interposing-relay board every time you need to read a 230 V contactor auxiliary or drive a solenoid valve directly. This controller reads 115/230 V AC inputs and switches mains loads on triac and relay outputs from the same terminal strip, which is precisely why OEMs specify it for packaged chillers and rooftop units — fewer parts in the panel and less to fail.

Interfaces

10/100 Mbit Ethernet (RJ45) for browser and IP tooling; RS-485 Modbus RTU, galvanically separated, with software-switchable termination; KNX TP1 process bus (max 700 m between nodes, 1,000 m total); full-modem RS-232 service port; SD/SDHC card slot, 128 MB to 32 GB, FAT16/FAT32, for application and firmware upgrades; local RJ45 service port with USB tool communication; peripheral bus for up to 31 extension modules (10 or fewer recommended, 30 m total cable); and up to three communication modules for Modbus, BACnet, LON or M-bus.

Published physical and environmental data

Dimensions 207 × 110 × 79 mm with HMI. Weight 450 g with HMI. Supply 24 V AC ±20 % or 24 V DC ±10 %, 45–65 Hz; current draw max 1.8 A at 24 V AC or 1.0 A at 24 V DC without extension modules; external fuse max 6.3 A slow. Operating range −40 to +70 °C, restricted to −20 to +60 °C because the LCD is fitted, −25 to +70 °C where the process bus is used. Humidity below 90 % RH non-condensing. IP20, protection class II, reinforced insulation 3750 V AC to EN 60730-1. Published MTBF 24 years. UL 916 and UL 873; CSA C22.2 No. 205. Integrated HMI: 144 × 64 pixel backlit LCD, roll-and-push knob and three function buttons. Real-time clock backed for at least 3 days by internal gold cap, or 200 days with the accessory battery. Base is pigeon-blue RAL 5014, housing light-grey RAL 7035.

What is included — check this against a new-in-box price:
Siemens ships new POL687 controllers without terminal plugs; the plug sets (POL068.75/STD screw type or POL068.76/STD spring-cage) are separately ordered items. On this unit the pluggable terminal blocks are present and fitted, including the orange 24 V supply plug — which removes a real cost and lead-time item. Not included: extension modules, communication modules, SD card, HMI cable, USB service cable (POL0C2), SAPRO programming licence (ACX93.000), or documentation.

Programming and firmware caution

Climatix controllers are freely programmable using the Siemens SAPRO graphical tool, but the /MCQ variant ships with Daikin/McQuay application firmware. If you are replacing a MicroTech III unit controller in a Daikin chiller or air handler, that is exactly what you want. If you intend to write your own application, the /STD variant is the correct base part. Confirm the application and firmware version against the machine before installing.

Interchange guidance

Also written POL687.70/MCQ, POL68770MCQ, POL 687.70/MCQ, MicroTech III MT3006, MT3006. Related: POL687.00/MCQ (same controller, no HMI), POL687.70/STD (freely programmable standard variant), POL688.10/STD.

Source-data note: the previous title and description described this as a “Logic Controller I/O Module” and a “PLC Processor Module from the Automate controller platform”. It is a Climatix 600 base controller — not an I/O module — and there is no “Automate” platform involved; both have been corrected. Made in Switzerland is consistent with Siemens Switzerland Ltd, Zug, and has been retained.