Previous documentation — kept for historical comparison. The standard rebuild wiring is now Reference Electrical Wiring R1, including new distribution blocks and all terminal assignments. Do not use this older record as the current rebuild specification. Return to Electrical Overview.

HEATING RATE CONTROLLER / ENGINEERING CHANGE RECORD / 22 OCTOBER 2026

22 October wiring record archive

A practical supplement to the original D12 eleven-sheet schematic set. Applies to the proposed two-channel cabinet and physical wiring reported on 22 October 2026. The original D12 PDF, PowerPoint and image viewer are superseded for the affected terminal and routing details but remain useful as historical schematic references.

ARCHIVED D13 FIELD WORKSHEET — NOT CURRENT WIRING INSTRUCTIONS. Use the R1.2 drawings, connection schedule and terminal distribution for current maintenance references. Manufacturer-verified: Finder 13.61 12–24 V type uses A1/A2 for supply and 3/ON/OFF control, 11/12/14 contacts; Weidmüller 8950770000 uses 13 = high-side output (+) and 14 = low-side output (−); Crydom DR2220D30U uses +3/A1 and −4/A2 for its control input. Reported, not inspected: Crydom +3 shares the EAO pushbutton central contact positive; Crydom −4 and ACTIVE LED− share Weidmüller 13. Still proposed: physical distribution layout, exact terminal stamps, ACTIVE LED+, mains routing, ferrules and final wiring. Power must remain isolated until independently checked.

The 4-page PDF is a condensed printable register (12 mains + 17 CH1 + 17 CH2 individual paths and release holds). The website below includes the more detailed context. Both remain draft engineering documents.

Print on A4 landscape. Individual routes have a blank tick box and an inspection record field. Printed checks do not make this an approved wiring drawing.

WORKSHEET A · MAINS AND PROTECTIVE EARTH

One cabinet, three L take-offs and three N take-offs

The three Live distribution take-offs are PSU, Channel 1 selector input and Channel 2 selector input. The three Neutral distribution take-offs are PSU, E1 and E2. In addition, there are two switched-live wires from the selectors to their Omrons, an incoming L/N feed, and individual protective-earth bonds. The take-off counts are not the complete number of individual conductors.

230 V AC. X1 is a logical distribution name, not an allocated numbered terminal strip. Verify fused/switched inlet poles, selector contact markings, conductor sizing, branch protection, PE continuity and the actual PS1/Omron terminals. Never bridge PE and N or AC neutral and 24 V DC 0 V.

✓	Wire / path ID	FROM	TO	Purpose	Actual terminal / check
□	AC-IN-L	J1 switched/fused L	X1 Live bus	Incoming feed	Proposed; J1 rear terminal mapping unverified
□	AC-IN-N	J1 switched Neutral	X1 Neutral bus	Incoming return	Proposed; J1 pole mapping unverified
□	AC-PS-L	X1 Live bus	PS1 mains L (C1)*	1 of 3 L take-offs	Physical PSU designation to be read on label
□	AC-S1-L	X1 Live bus	S1 mains NO contact input*	2 of 3 L take-offs	Exact selector contact markings to check
□	AC-S2-L	X1 Live bus	S2 mains NO contact input*	3 of 3 L take-offs	Exact selector contact markings to check
□	AC-PS-N	X1 Neutral bus	PS1 mains N (C2)*	1 of 3 N take-offs	Physical PSU designation to be read on label
□	AC-E1-N	X1 Neutral bus	E1 Omron terminal 12 (N)*	2 of 3 N take-offs	Confirm E1 fitted variant and legend
□	AC-E2-N	X1 Neutral bus	E2 Omron terminal 12 (N)*	3 of 3 N take-offs	Confirm E2 fitted variant and legend
□	AC-E1-L	S1 mains NO contact output*	E1 Omron terminal 11 (L)*	Additional switched Live wire	This is NOT another X1 Live take-off
□	AC-E2-L	S2 mains NO contact output*	E2 Omron terminal 11 (L)*	Additional switched Live wire	This is NOT another X1 Live take-off
□	AC-PE-1	J1 PE	PE distribution	Protective earthing	Separate from N and 24 V 0 V; safety-critical
□	AC-PE-2	PE distribution	PS1 FG/PE, enclosure, door and required bonds	Multiple PE conductors	Use individual labelled, tested protective bonds; verify terminals

Cabinet ID __________ Wire tags checked by __________ Independent electrical inspection __________ Date __________

WORKSHEET B · CHANNEL 1 CONTROL (0–24 V)

Channel 1: proposed physical wire connections

There are 3 reported available +24 V distribution positions and 3 reported available 0 V positions per channel. This is a capacity constraint, not a verified terminal-block allocation. Some destinations share junctions. The shared positive at the EAO pushbutton/Crydom and the shared Crydom/ACTIVE negative at Weidmüller 13 were reported by the builder; the specific terminal and both channels have not been inspected.

Status: user-reported cabling ≠ continuity-tested. Verify the EAO central pin really is COM; each double/twin ferrule, jumper and terminal must explicitly support the conductor count and cross-section. Weidmüller PUSH IN terminals are not permission to insert two conductors together. All remaining entries are proposed unless signed off.

✓	Wire / path ID	FROM	TO	Purpose	Actual terminal / check
□	C1-DC-01	X2 shared +24 V	S1 24 V selector B input*	Permanent +24 V in	Contact terminal stamps unknown
□	C1-DC-02	S1 24 V selector B output*	X3 channel +24 V rail	Gated +24 V	Not the same as EN1 relay-enabled net
□	C1-P1	X3 gated +24 V	K1 Finder 13.61 A1	Switched +24 V destination	13.61 L/+ in original D12 was NOT a device terminal
□	C1-P2	X3 gated +24 V	K1 Finder 13.61 11	Switched +24 V destination	Contact common 11
□	C1-P3	X3 gated +24 V	SB1 EAO momentary COM*	Switched +24 V destination	User describes a central contact pin; physical stamp not yet confirmed
□	C1-P4	SB1 COM / same verified switched +24 V junction	SSR1 Crydom +3/A1	Crydom control positive	USER-REPORTED shared positive at button contact; verify both channels
□	C1-P5	X3 gated +24 V / Crydom +3 junction	HL1 ACTIVE indicator +	ACTIVE positive	INTENDED connection; installation not confirmed
□	C1-N1	X3 0 V	K1 Finder 13.61 A2	Common control 0 V	13.61 N/− in D12 was NOT a device terminal
□	C1-N2	X3 0 V	K3 Finder 62.31 coil A2*	Common 0 V	Socket and suppression mapping unverified
□	C1-N3	X3 0 V	SB1 EAO ENABLE indicator LED−	Common 0 V	Not the ACTIVE indicator negative
□	C1-N4	X3 0 V	W1 Weidmüller output 14	Common 0 V	Output 14 is the low/negative side per manufacturer drawing
□	C1-E1	SB1 momentary NO*	K1 Finder 13.61 terminal 3	Pulse command	Actual EAO stamp to check
□	C1-E2	K1 Finder 13.61 output 14	K3 Finder 62.31 coil A1*	Enabled net EN1	Finder 13.61 NO output; socket terminal mapping to verify
□	C1-E3	K1 Finder 13.61 output 14	SB1 ENABLE indicator LED+	Enabled net EN1	Three-way logical net with K3 A1; junction method unverified
□	C1-S1	SSR1 Crydom −4/A2	W1 Weidmüller output 13	SSR switched return	USER-REPORTED; verify actual W module identification
□	C1-S2	HL1 ACTIVE indicator −	W1 Weidmüller output 13 / SSR1 −4 junction	ACTIVE switched return	USER-REPORTED; confirm both channels and lamp identity
□	C1-O1	E1 Omron control-output 1(+) / 2(−)*	W1 input A1(+) / A2(−)	12 V command input	Controller hardware-dependent outputs must be verified

Channel 1 installer __________ Inspector __________ Test sheet __________ Date __________

WORKSHEET C · CHANNEL 2 CONTROL (0–24 V)

Channel 2: proposed physical wire connections

✓	Wire / path ID	FROM	TO	Purpose	Actual terminal / check
□	C2-DC-01	X2 shared +24 V	S2 24 V selector B input*	Permanent +24 V in	Contact terminal stamps unknown
□	C2-DC-02	S2 24 V selector B output*	X4 channel +24 V rail	Gated +24 V	Not the same as EN2 relay-enabled net
□	C2-P1	X4 gated +24 V	K2 Finder 13.61 A1	Switched +24 V destination	13.61 L/+ in original D12 was NOT a device terminal
□	C2-P2	X4 gated +24 V	K2 Finder 13.61 11	Switched +24 V destination	Contact common 11
□	C2-P3	X4 gated +24 V	SB2 EAO momentary COM*	Switched +24 V destination	User describes a central contact pin; physical stamp not yet confirmed
□	C2-P4	SB2 COM / same verified switched +24 V junction	SSR2 Crydom +3/A1	Crydom control positive	USER-REPORTED shared positive at button contact; verify both channels
□	C2-P5	X4 gated +24 V / Crydom +3 junction	HL2 ACTIVE indicator +	ACTIVE positive	INTENDED connection; installation not confirmed
□	C2-N1	X4 0 V	K2 Finder 13.61 A2	Common control 0 V	13.61 N/− in D12 was NOT a device terminal
□	C2-N2	X4 0 V	K4 Finder 62.31 coil A2*	Common 0 V	Socket and suppression mapping unverified
□	C2-N3	X4 0 V	SB2 EAO ENABLE indicator LED−	Common 0 V	Not the ACTIVE indicator negative
□	C2-N4	X4 0 V	W2 Weidmüller output 14	Common 0 V	Output 14 is the low/negative side per manufacturer drawing
□	C2-E1	SB2 momentary NO*	K2 Finder 13.61 terminal 3	Pulse command	Actual EAO stamp to check
□	C2-E2	K2 Finder 13.61 output 14	K4 Finder 62.31 coil A1*	Enabled net EN2	Finder 13.61 NO output; socket terminal mapping to verify
□	C2-E3	K2 Finder 13.61 output 14	SB2 ENABLE indicator LED+	Enabled net EN2	Three-way logical net with K4 A1; junction method unverified
□	C2-S1	SSR2 Crydom −4/A2	W2 Weidmüller output 13	SSR switched return	USER-REPORTED; verify actual W module identification
□	C2-S2	HL2 ACTIVE indicator −	W2 Weidmüller output 13 / SSR2 −4 junction	ACTIVE switched return	USER-REPORTED; confirm both channels and lamp identity
□	C2-O1	E2 Omron control-output 1(+) / 2(−)*	W2 input A1(+) / A2(−)	12 V command input	Controller hardware-dependent outputs must be verified

Channel 2 installer __________ Inspector __________ Test sheet __________ Date __________

WORKSHEET D · SUPPLY DISTRIBUTION, JUNCTIONS & RELEASE CHECKS

Distribution counts, actual junction choices and checks

230 V mains distribution — cabinet total

3 X1 Live outgoing positions: PS1 L; S1 mains contact input; S2 mains contact input. 3 X1 Neutral outgoing positions: PS1 N; E1 N; E2 N. Also: J1 incoming L/N, selector outputs to E1/E2 Live, separate PE distribution and bonding.

Whether the installed strips have sufficient physical terminals depends on how the incoming and cross-connected feeds are landed. Count both input and output positions. Never treat N as PE.

24 V distribution — per channel

3 gated +24 V take-off positions and 3 common 0 V take-off positions reported as physically available, not yet inspected.

Illustrative grouping: +1 K1 A1 and 11; +2 SB1 COM and Crydom +3; +3 ACTIVE+; 0V1 K1 A2; 0V2 K3 A2 and ENABLE LED−; 0V3 Weidmüller 14. Alternative approved jumpers are permitted. EN1/EN2 are distinct relay-enabled junctions.

Do not confuse the three positive circuits

+24 shared: always available from PS1 while control supply is on. +24 gated: available after the channel's CONTROL selector. EN1/EN2: only available after Finder 13.61 output 14 closes; supplies K3/K4 A1 and EAO ENABLE LED+.

The ACTIVE lamp is the SSR demand indicator, not actual heater-current proof.

Weidmüller verified topology

Input A1 (+12 V)/A2 (−12 V) is driven by the Omron SSR command. Output transistor terminals 13 (+) and 14 (−) complete the series path +24 gated → Crydom +3 / ACTIVE+ → Crydom −4 / ACTIVE− → W13 → W14 → 0V. Its manufacturer gives 5–48 V DC load, 100 mA maximum; Crydom input up to 15 mA and proposed ACTIVE lamp up to 20 mA (35 mA combined worst-case), subject to actual installed lamp/type and protection.

Connector / ferrule rules

Do not assume two conductors are allowed in one clamp. Check the exact terminal-block maker's permitted conductor count, twin-ferrule dimensions, clamp capacity, strip length and torque. The Weidmüller output is PUSH IN; manufacturer instructions depict two side-by-side inserted wires as incorrect. Use approved distribution junctions where necessary. No X1–X4 numbered terminal assignment has been confirmed.

Mandatory evidence before release

Photograph stamped terminals on both Finder 13.61 devices and the EAO contact blocks
Verify actual X1–X4 terminal-strip and junction allocation; apply wire markers
Dead continuity/insulation and PE bonding test by competent person
Verify Weidmüller polarity, SSR demand and LEDs with a safe, low-energy test
Prove control-power loss/return cannot re-enable heater, including held pushbutton
Verify emergency isolation, protection coordination, 15 A duty and heat dissipation
Record as-built, independent review, and revision approval

Legacy schematic correction: old D12 K1/K2 “L/+” and “N/−” = external supply rails, not relay terminals. They map to A1 and A2 only for the confirmed 13.61.0.024.0000 variant. Complete relay code still needs physically checking. This document does not change the D12 PDF/PPTX files themselves.

Inspection checklist signed __________ Drawing issue approved __________ Revision / date __________